summary
See #35816 for a PR that forces esbuild to be true and has all of CI green. Adds in one important fix for EXP_C, and then two fixes that only matter when it is the primary bundler:

1. (important): accept either unminified or minified name for getAmpConfigForFile. The distinction wasn't useful and forced us to pass in the minified name for minified builds (srcFilename is more ergonomic). Instead I pass destFilename
2. visual-diff:test:true check should also allow !0 since that is the minified version of true
3. check-sourcemaps: esbuild has first line of the output on the first line instead of the second.

confidence checks

• prop mangling has been disabled for now. this is the riskiest optimization we could do, and my goal now is to create a baseline of how this branch performs without it. If equivalent to the closure version, we can then pursue mangling separately.
• all automated tests pass
• manual testing of many sites (ping for details)
• full manual qa pass