Add back missing api_connextion/__init__.py file (#12240)

A bad rebase in #12082 deleted this file by mistake.

This missing file was also the cause of needing the documentation
to exclude these files

Fixes #12239

airflow/api_connexion/__init__.py

@@ -0,0 +1,16 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, 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.

docs/conf.py

@@ -123,14 +123,6 @@
     "_api/airflow/providers/cncf/index.rst",
     # Packages without operators
     "_api/airflow/providers/sendgrid",
-    # Other API rst files.
-    "_api/endpoints/index.rst",
-    "_api/endpoints/*/index.rst",
-    "_api/exceptions/index.rst",
-    "_api/parameters/index.rst",
-    "_api/schemas/index.rst",
-    "_api/schemas/*/index.rst",
-    "_api/security/index.rst",
     # Templates or partials
     'autoapi_templates',
     'howto/operator/google/_partials',