Remove git-clean subcommand of Rust build script

[vitvakatu]

Pull Request Description

Removes ./run git-clean. You can use pnpm run git-clean [--verbose] [--clean-bazel] instead. It does require neither pnpm install nor Rust script compilation.

Ideally, we wouldn’t clean Bazel at all times, but for simplicity, I preserved legacy behavior.

JVM tests job now always does a clean build, but I removed invocation of git-clean from ./run backend test jvm. It solves the issue with cleaning the Rust binary on Windows while it is being used. In the future, we won’t have this problem anyway. Always cleaning in JVM tests job is required as per @Akirathan.

Important Notes

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  TypeScript,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• Unit tests have been written where possible.
• If meaningful changes were made to logic or tests affecting Enso Cloud integration in the libraries,
  or the Snowflake database integration, a run of the Extra Tests has been scheduled.
  • If applicable, it is suggested to paste a link to a successful run of the Extra Tests.