When checking the version of the doxygen installed from conda the output
has the following format:
1.9.2 (ee54ebd4f0ad83d9c44f19a459146de64d0ffba2*)
This would cause an error in the "Missing API docs" CI job. This fix
will correctly parse the doxygen version for both stable releases
("1.9.2") as well as the version with the git commit hash attached.