chore: revert "feat: [google-cloud-network-security] publish v1alpha1 Network Security API client and ClientTlsPolicy API resource" (#14093)

Reverts #14090

Reason: this sub-API needed some changes to BUILD rules. Googlers: see
cl/782025592

Author: vchudnov-g

packages/google-cloud-network-security/docs/index.rst

@@ -22,14 +22,6 @@ API Reference
     network_security_v1beta1/services_
     network_security_v1beta1/types_
 
-API Reference
--------------
-.. toctree::
-    :maxdepth: 2
-
-    networksecurity_v1alpha1/services_
-    networksecurity_v1alpha1/types_
-
 
 Changelog
 ---------

packages/google-cloud-network-security/docs/networksecurity_v1alpha1/network_security.rst

@@ -13,4 +13,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-__version__ = "0.0.0"  # {x-release-please-version}
+__version__ = "0.9.18"  # {x-release-please-version}

packages/google-cloud-network-security/docs/networksecurity_v1alpha1/services_.rst

@@ -13,4 +13,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-__version__ = "0.0.0"  # {x-release-please-version}
+__version__ = "0.9.18"  # {x-release-please-version}

packages/google-cloud-network-security/docs/networksecurity_v1alpha1/types_.rst

@@ -13,4 +13,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-__version__ = "0.0.0"  # {x-release-please-version}
+__version__ = "0.9.18"  # {x-release-please-version}