Fully switch to bazel 6.0.0 in all places (#960)

Author: aignas

examples/BUILD.bazel

@@ -51,5 +51,5 @@ bazel_integration_test(
 bazel_integration_test(
     name = "bzlmod_example",
     bzlmod = True,
-    override_bazel_version = "6.0.0rc1",
+    override_bazel_version = "6.0.0",
 )

examples/bzlmod/.bazelversion

@@ -1 +1 @@
-6.0.0rc1
+6.0.0

internal_setup.bzl

@@ -31,13 +31,6 @@ def rules_python_internal_setup():
     # Depend on the Bazel binaries for running bazel-in-bazel tests
     bazel_binaries(versions = SUPPORTED_BAZEL_VERSIONS)
 
-    # Bazel 5.3.0 has bzlmod bugs so we use 6.0 prerelease for the bzlmod example.
-    # SUPPORTED_BAZEL_VERSIONS doesn't currently support multiple versions. For now,
-    # we only want to run the bzlmod example with a separate version.
-    bazel_binaries(versions = [
-        "6.0.0rc1",
-    ])
-
     bazel_skylib_workspace()
 
     # gazelle:repository_macro gazelle/deps.bzl%gazelle_deps