Workflow updates

- Do not re-run PR tests on edited PRs
- Close added/fixed issues on published release
- Issues stale after 60 days instead of 30, close after 10 days instead of 5
- Use Vankka/pr-target-branch-action for checking that PR is made to proper branch
- Add version number to sphinx config, must use cmake to configure the file
- Add jobs to readthedocs.yaml configuration

.readthedocs.yaml

@@ -10,6 +10,11 @@ build:
   os: ubuntu-20.04
   tools:
     python: "3.9"
+  jobs:
+    post_system_dependencies:
+      - apt-get install cmake
+    pre_create_environment:
+      - cmake ..
 
 # Build documentation in the docs/ directory with Sphinx
 sphinx: