[8.6.0] Add `--experimental_strict_repo_env` option

[bazel-io]

Forked from #24404

[bazel-io]

Cherry-pick was attempted but there were merge conflicts in the following file(s). Please resolve manually.

src/main/java/com/google/devtools/build/lib/bazel/BazelRepositoryModule.java
src/main/java/com/google/devtools/build/lib/bazel/bzlmod/RegularRunnableExtension.java
src/main/java/com/google/devtools/build/lib/bazel/repository/RepositoryFetchFunction.java
src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java
src/main/java/com/google/devtools/build/lib/runtime/CommonCommandOptions.java
src/main/java/com/google/devtools/build/lib/skyframe/packages/BazelPackageLoader.java
src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisMock.java
src/test/java/com/google/devtools/build/lib/bazel/bzlmod/DiscoveryTest.java
src/test/java/com/google/devtools/build/lib/bazel/bzlmod/ModuleFileFunctionTest.java
src/test/java/com/google/devtools/build/lib/rules/repository/RepositoryDelegatorTest.java
src/test/java/com/google/devtools/build/lib/skyframe/ContainingPackageLookupFunctionTest.java
src/test/java/com/google/devtools/build/lib/skyframe/FileFunctionTest.java
src/test/java/com/google/devtools/build/lib/skyframe/PackageLookupFunctionTest.java

cc: @bazelbuild/triage

[Wyverald]

@Silic0nS0ldier mind taking a crack at cherry picking?

[hemantmeena2005]

I would like to look into this

[Silic0nS0ldier]

Took me a little bit to find the time to address conflicts (git and semantic, there have been a lot of refactorings in the jump from v8 to v9) but it's now ready #28189.