Upgrade antsibull-docs to 1.6.1 (#78872)

* Bump antsibull-docs version to 1.6.0 to fully support filter docs.

* known_good_reqs.txt no longer exists.

* Bump version to 1.6.1.

docs/docsite/requirements.txt

@@ -1,7 +1,8 @@
 # pip packages required to build docsite
 # these requirements are as loosely defined as possible
 # if you want known good versions of these dependencies
-# use known_good_reqs.txt instead
+# use test/sanity/code-smell/docs-build.requirements.txt
+# instead
 
 antsibull-docs >= 1.0.0, < 2.0.0
 docutils

test/sanity/code-smell/docs-build.requirements.in

@@ -6,4 +6,4 @@ sphinx-notfound-page
 sphinx-ansible-theme
 straight.plugin
 rstcheck < 4  # match version used in other sanity tests
-antsibull-docs == 1.5.0  # currently approved version
+antsibull-docs == 1.6.1  # currently approved version

test/sanity/code-smell/docs-build.requirements.txt

@@ -5,7 +5,7 @@ aiosignal==1.2.0
 alabaster==0.7.12
 ansible-pygments==0.1.1
 antsibull-core==1.2.0
-antsibull-docs==1.5.0
+antsibull-docs==1.6.1
 async-timeout==4.0.2
 asyncio-pool==0.6.0
 attrs==22.1.0