Increase min tested Bazel version to 4.0.0

[UebelAndre]

🚀 feature request

Relevant Rules

Description

A clear and concise description of the problem or missing capability...

Writing tests and new features for these rules is difficult since there are a few new features (for me, the env attribute and json module) that are incredibly useful pretty un-fun to work around, making changes take more time than the need to. The min tested version should be bumped to 4.0.0 to enable the use of these features.

Describe the solution you'd like

If you have a solution in mind, please describe it.

Update the bazel versions in .bazelrc and version.bzl to 4.0.0

Describe alternatives you've considered

Have you considered any alternative solutions or workarounds?

Alternatively, it'd be nice to have a well documented way to conditionally use things in newer versions of Bazel. Perhaps native.bazel_version could be made available to rules and macros (not just repository rules) (bazelbuild/bazel#8305) but that would likely also require some way to compare versions which I'm only aware of @bazel_skylib//lib:versions.bzl.

[alexeagle]

Agreed - it's a breaking change for users, but we made the same in rules_nodejs to reduce support burden. LTS and rolling releases are the only ones I think we need to support.