This upgrade brings several performance improvements and bug fixes:

#### Performance improvements
- remote execution: bazelbuild/bazel#27564
- module extensions: bazelbuild/bazel#27296

#### Reliability improvements
- cache invalidation: bazelbuild/bazel#27417
- configuration: bazelbuild/bazel#27128
- Git repositories: bazelbuild/bazel#27705
- query:
  - bazelbuild/bazel#27560
  - bazelbuild/bazel#27117
- registry mirrors: bazelbuild/bazel#27531

#### Bug fixes
- remote cache: bazelbuild/bazel#27996
- repository handling: bazelbuild/bazel#27995
- repository cache: bazelbuild/bazel#28161
- local execution: bazelbuild/bazel#27994

This upgrade brings several performance improvements and bug fixes:

## Performance improvements (8.5.0)
- Remote execution: Add --remote_max_concurrency_per_connection flag to control concurrent gRPC requests (default: 100)
  bazelbuild/bazel#27564
- Module extensions: Support storing/retrieving JSON-like Starlark objects without invalidation, reducing unnecessary rebuilds
  bazelbuild/bazel#27296

## Reliability improvements (8.5.0)
- Cache invalidation: Source directory contents now tracked for proper invalidation
  bazelbuild/bazel#27417
- Configuration: Add ctx.configuration.short_id for identifying configurations
  bazelbuild/bazel#27128
- Git repositories: git_repository now checks out default branch when unspecified
  bazelbuild/bazel#27705
- Query: Add executables() function and fix genquery for external repos
  bazelbuild/bazel#27560
  bazelbuild/bazel#27117
- Registry mirrors: --module_mirrors now supports per-registry mirror specification
  bazelbuild/bazel#27531

## Bug fixes (8.5.1)
- Remote cache: Add option to continue with local execution if remote cache is unavailable
  bazelbuild/bazel#27996
- Repository handling: Fix crash when mixing use_repo_rule and --inject_repository
  bazelbuild/bazel#27995
- Repository cache: Fix permission denied issue with --experimental_repository_cache_hardlinks
  bazelbuild/bazel#28161
- Local execution: Fix incorrect SkyframeLookupResult usage
  bazelbuild/bazel#27994

Both 8.5.0 and 8.5.1 are fully backward compatible with Bazel 8.0.

## Dependency updates
- Upgrade rules_go from 0.57.0 to 0.59.0 for Bazel 8.5+ compatibility
  bazel-contrib/rules_go#4493
- Configure sh_configure extension for rules_shell to auto-detect shell toolchain

## Platform-specific changes
- Windows: Configure hermetic shell via --repo_env=BAZEL_SH which is used by both
  sh_configure (sh_binary/sh_test) and --shell_executable (genrule/run_shell).
  This eliminates dependency on system environment variables.
- Windows: Disable code coverage collection (--nocollect_code_coverage) to avoid
  shell toolchain issues. Coverage requires sh_binary (collect_coverage) which
  needs a hermetic shell toolchain not yet available.
  bazelbuild/rules_shell#4

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

This upgrade brings several performance improvements and bug fixes:

#### Performance improvements
- remote execution: bazelbuild/bazel#27564
- module extensions: bazelbuild/bazel#27296

#### Reliability improvements
- cache invalidation: bazelbuild/bazel#27417
- configuration: bazelbuild/bazel#27128
- Git repositories: bazelbuild/bazel#27705
- query:
  - bazelbuild/bazel#27560
  - bazelbuild/bazel#27117
- registry mirrors: bazelbuild/bazel#27531

#### Bug fixes
- remote cache: bazelbuild/bazel#27996
- repository handling: bazelbuild/bazel#27995
- repository cache: bazelbuild/bazel#28161
- local execution: bazelbuild/bazel#27994

### What does this PR do?
Bump `bazel` version from [8.4.2](https://github.com/bazelbuild/bazel/releases/tag/8.4.2) to [8.5.1](https://github.com/bazelbuild/bazel/releases/tag/8.5.1).

To make that happen, we also need to:
- specify which `bash` to use on Windows when evaluating **repository** rules, for compatibility with bazelbuild/bazel#26927:
  ```
  ERROR: /path/to/external/bazel_tools/tools/test/BUILD:23:10: in sh_binary rule @@bazel_tools//tools/test:collect_coverage: 
  Error in fail: No suitable shell toolchain found:
  * if you are running Bazel on Windows, set the BAZEL_SH environment variable to the path of bash.exe
  ```
  (actual job output: https://gitlab.ddbuild.io/DataDog/datadog-agent/-/jobs/1349246422#L77)
- bump `rules_go` from (implicit) [0.57.0](https://github.com/bazel-contrib/rules_go/releases/tag/v0.57.0) to (explicit) [0.59.0](https://github.com/bazel-contrib/rules_go/releases/tag/v0.59.0) for bazel-contrib/rules_go/pull/4493 to be compatible with bazelbuild/bazel/pull/27296:
  ```
  Error: 'Facts' value has no field or method 'clear'
  ```

### Motivation
1. this upgrade alone brings several improvements and bug fixes, among which:
- bazelbuild/bazel#27117
- bazelbuild/bazel#27296
- bazelbuild/bazel#27417, covers:
  - bazelbuild/bazel#25834
  - bazelbuild/bazel#25863
  - bazelbuild/bazel#25864
  - bazelbuild/bazel#25870
  - bazelbuild/bazel#26698
- bazelbuild/bazel#27531
- bazelbuild/bazel#27560
- bazelbuild/bazel#27564
- bazelbuild/bazel#27705
- bazelbuild/bazel#27995
- bazelbuild/bazel#27996

2. `bazel` 9.0 is due soon, so better off favoring incremental bumps.

### Additional Notes
Leveraging [the latter](bazelbuild/bazel#27996) might allow us to later reconsider whether we'd like to go back to the `--remote_cache` flag (instead of the `--remote_executor` flag that we had to switch to in #44962).

Co-authored-by: regis.desgroppes <regis.desgroppes@datadoghq.com>