Add support for filtering packages based on their minimum age, similar to
pnpm's `minimumReleaseAge` feature. This helps reduce the risk of installing
compromised packages by delaying the installation of newly published versions.

In most cases, malicious releases are discovered and removed from channels
within a short time window (often within an hour). By requiring packages to
have been published for a minimum duration, users can give the community time
to identify and report malicious packages before they are installed.

## New API

Added `MinimumAgeConfig` struct with the following fields:
- `min_age: Duration` - The minimum age a package must have
- `now: DateTime<Utc>` - Reference time for calculating cutoff (defaults to current time)
- `exempt_packages: HashSet<PackageName>` - Packages exempt from the check

Added `min_age: Option<MinimumAgeConfig>` field to `SolverTask`.

## Example Usage

```rust
use std::time::Duration;
use rattler_solve::MinimumAgeConfig;

// Only allow packages published at least 1 hour ago
let config = MinimumAgeConfig::new(Duration::from_secs(60 * 60))
    .with_exempt_package("my-trusted-package".parse().unwrap());
```

## Implementation

- Implemented in both `resolvo` and `libsolv_c` backends
- Packages newer than `now - min_age` are excluded from the solve
- Exempt packages bypass the age check
- Clear error messages indicate when packages are excluded due to age

…e-filter-01Jnto7XmZCZchzwpL3A25nu

# Conflicts:
#	Cargo.lock
#	py-rattler/Cargo.lock