docs: update Sphinx requirements in ipasphinx package

One-liner rule to update ipasphinx dependency as we are using m2r2
package which is compatible with newer Sphinx.

Fixes: https://pagure.io/freeipa/issue/9148

Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>

ipasphinx/setup.py

@@ -16,6 +16,5 @@ if __name__ == "__main__":
         doc=__doc__,
         package_dir={"ipasphinx": ""},
         packages=["ipasphinx"],
-        # m2r is not compatible with Sphinx 3.x yet
-        install_requires=["ipaserver", "ipalib", "sphinx < 3.0", "m2r"],
+        install_requires=["ipaserver", "ipalib", "sphinx", "m2r2"],
     )