Bazel: Upgrade to bazel 8.

.bazelrc

@@ -1,5 +1,4 @@
 common --enable_platform_specific_config
-common --enable_bzlmod
 # because we use --override_module with `%workspace%`, the lock file is not stable
 common --lockfile_mode=off
 
@@ -25,6 +24,5 @@ common --registry=https://bcr.bazel.build
 
 common --@rules_dotnet//dotnet/settings:strict_deps=false
 common --experimental_isolated_extension_usages
-common --incompatible_use_plus_in_repo_names
 
 try-import %workspace%/local.bazelrc