Fix typo (minor)

Author: tomka

sphinx-doc/source/release.rst

@@ -12,7 +12,7 @@ This release branch can then be pushed to the main repository to have CI test
 it. Once it passes all tests it can be merged into the master/main branch.
 
 As part of the release script the release commit is also tagged with the release
-name (e.g. ``2021.12.20``). This tag jas to be pushed manually to GitHub and the
+name (e.g. ``2021.12.20``). This tag has to be pushed manually to GitHub and the
 ``stable`` tag has to be updated as well::
 
   git push origin <tag-name>