Fix bugs in ansible-test units command. (#24044)

* Handle old versions of coverage.
* Handle old versions of setuptools.
* Detect python version for docker/remote units.
* Add sanity override for test constraints.

test/sanity/code-smell/test-constraints.sh

@@ -2,6 +2,7 @@
 
 constraints=$(
     grep '.' test/runner/requirements/*.txt \
+        | grep -v '(sanity_ok)$' \
         | sed 's/ *;.*$//; s/ #.*$//' \
         | grep -v '/constraints.txt:' \
         | grep '[<>=]'