Update cc_static_library.bzl to no longer be experimental

Copybara Import from https://github.com/bazelbuild/rules_cc/pull/719

BEGIN_PUBLIC
Update cc_static_library.bzl to no longer be experimental (#719)

This has been stable for at least a year.

Closes #719
END_PUBLIC

COPYBARA_INTEGRATE_REVIEW=https://github.com/bazelbuild/rules_cc/pull/719 from fmeum:patch-2 ec224fa311e9a4b58ce5a85213755d950058e296
PiperOrigin-RevId: 916358637
Change-Id: Ic04308d0e4241f83b688c5d8d761b460e0c1021d

cc/private/rules_impl/cc_static_library.bzl

diff --git a/cc/private/rules_impl/cc_static_library.bzl b/cc/private/rules_impl/cc_static_library.bzl
index a171488..db327bd 100644
--- a/cc/private/rules_impl/cc_static_library.bzl
+++ b/cc/private/rules_impl/cc_static_library.bzl
@@ -11,11 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-"""This is an experimental implementation of cc_static_library.
-
-We may change the implementation at any moment or even delete this file. Do not
-rely on this.
-"""
+"""The implementation of cc_static_library."""
 
 load("@bazel_skylib//lib:paths.bzl", "paths")
 load("//cc:action_names.bzl", "ACTION_NAMES")