Bump bazel version to 8.6.0 for own fix

### What does this PR do?
Bump `.bazelversion` from 8.5.1 to 8.6.0.

### Motivation
Selected changes between 8.5.1 and 8.6.0:
- Fix visibility for implicit deps of parent rules (bazelbuild/bazel#28722)
- Force rctx.{download_and,}extract to create user-readable files (bazelbuild/bazel#28551)
- Fix disk cache failures on concurrent read-write access on Windows (bazelbuild/bazel#28529)
- Add a target_type argument to ctx.actions.symlink (bazelbuild/bazel#28538)
- Compensate for Windows filesystems lacking junction support (bazelbuild/bazel#28367)
  (our fix)
- Add short_uncached and detailed_uncached options to --test_summary (bazelbuild/bazel#28343)
- Add --experimental_strict_repo_env option (bazelbuild/bazel#28189)
- Make overlaid files executable in http_archive (bazelbuild/bazel#28277)
- Add bazel mod show_repo --all_repos and --all_visible_repos (bazelbuild/bazel#28012)
- Enable --experimental_retain_test_configuration_across_testonly (bazelbuild/bazel#28115)
- Add option to continue with local execution if remote cache is unavailable (bazelbuild/bazel#28001)

Author: rdesgroppes

.bazelrc

@@ -41,8 +41,6 @@ common:macos --remote_local_fallback_strategy=sandboxed
 
 # Windows config -------------------------------------------------------------------------------------------------------
 common:windows --strategy=standalone # Valid values are: [dynamic_worker, standalone, dynamic, remote, worker, local]
-# For whatever reason if convenience symlinks are present, the build fails on Windows.
-common:windows --noexperimental_convenience_symlinks
 # Neither repo_env nor shell_executable affect action keys. It can be both an advantage and a disadvantage.
 # For instance, if we need to have some special behavior in bash we can add it, however, in some cases
 # it may lead to cache poisoning.

.bazelversion

@@ -1 +1 @@
-8.5.1
+8.6.0