build: fix docs and docfx builds (#12200)

This PR updates the post processor image to the latest one which is
`gcr.io/cloud-devrel-public-resources/owlbot-python-mono-repo@sha256:1f42c1d6b70210540f55110662ae80e22b03dfb897782b09e546148599d3336c`.

The latest image fixes an issue with the docs and docfx builds. See
googleapis/synthtool#1916

Run the following commands to obtain the latest sha256
```
docker pull gcr.io/cloud-devrel-public-resources/owlbot-python-mono-repo:latest
```

```
docker inspect --format='{{.RepoDigests}}' gcr.io/cloud-devrel-public-resources/owlbot-python-mono-repo:latest
[gcr.io/cloud-devrel-public-resources/owlbot-python-mono-repo@sha256:1f42c1d6b70210540f55110662ae80e22b03dfb897782b09e546148599d3336c]
```

.github/.OwlBot.lock.yaml

@@ -13,4 +13,4 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-python-mono-repo:latest
-  digest: sha256:957ddc3272f6b8058ff0ca2e8692b56f0a764d804fd577670385d54f19ee43d6
+  digest: sha256:1f42c1d6b70210540f55110662ae80e22b03dfb897782b09e546148599d3336c

packages/google-cloud-config/noxfile.py

@@ -282,6 +282,15 @@ def docs(session):
 
     session.install("-e", ".")
     session.install(
+        # We need to pin to specific versions of the `sphinxcontrib-*` packages
+        # which still support sphinx 4.x.
+        # See https://github.com/googleapis/sphinx-docfx-yaml/issues/344
+        # and https://github.com/googleapis/sphinx-docfx-yaml/issues/345.
+        "sphinxcontrib-applehelp==1.0.4",
+        "sphinxcontrib-devhelp==1.0.2",
+        "sphinxcontrib-htmlhelp==2.0.1",
+        "sphinxcontrib-qthelp==1.0.3",
+        "sphinxcontrib-serializinghtml==1.1.5",
         "sphinx==4.5.0",
         "alabaster",
         "recommonmark",
@@ -308,6 +317,15 @@ def docfx(session):
 
     session.install("-e", ".")
     session.install(
+        # We need to pin to specific versions of the `sphinxcontrib-*` packages
+        # which still support sphinx 4.x.
+        # See https://github.com/googleapis/sphinx-docfx-yaml/issues/344
+        # and https://github.com/googleapis/sphinx-docfx-yaml/issues/345.
+        "sphinxcontrib-applehelp==1.0.4",
+        "sphinxcontrib-devhelp==1.0.2",
+        "sphinxcontrib-htmlhelp==2.0.1",
+        "sphinxcontrib-qthelp==1.0.3",
+        "sphinxcontrib-serializinghtml==1.1.5",
         "gcp-sphinx-docfx-yaml",
         "alabaster",
         "recommonmark",

packages/google-cloud-securitycentermanagement/noxfile.py

@@ -282,6 +282,15 @@ def docs(session):
 
     session.install("-e", ".")
     session.install(
+        # We need to pin to specific versions of the `sphinxcontrib-*` packages
+        # which still support sphinx 4.x.
+        # See https://github.com/googleapis/sphinx-docfx-yaml/issues/344
+        # and https://github.com/googleapis/sphinx-docfx-yaml/issues/345.
+        "sphinxcontrib-applehelp==1.0.4",
+        "sphinxcontrib-devhelp==1.0.2",
+        "sphinxcontrib-htmlhelp==2.0.1",
+        "sphinxcontrib-qthelp==1.0.3",
+        "sphinxcontrib-serializinghtml==1.1.5",
         "sphinx==4.5.0",
         "alabaster",
         "recommonmark",
@@ -308,6 +317,15 @@ def docfx(session):
 
     session.install("-e", ".")
     session.install(
+        # We need to pin to specific versions of the `sphinxcontrib-*` packages
+        # which still support sphinx 4.x.
+        # See https://github.com/googleapis/sphinx-docfx-yaml/issues/344
+        # and https://github.com/googleapis/sphinx-docfx-yaml/issues/345.
+        "sphinxcontrib-applehelp==1.0.4",
+        "sphinxcontrib-devhelp==1.0.2",
+        "sphinxcontrib-htmlhelp==2.0.1",
+        "sphinxcontrib-qthelp==1.0.3",
+        "sphinxcontrib-serializinghtml==1.1.5",
         "gcp-sphinx-docfx-yaml",
         "alabaster",
         "recommonmark",