Use sphinx>=7 and disable shallow clone in CI

It's needed to fix sphinx_last_updated_by_git in CI.

Author: gmelikov

.github/workflows/pull_request.yml

@@ -7,6 +7,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
     - name: Prepare
       run: |
         sudo apt-get update -y

docs/requirements.txt

@@ -1,4 +1,4 @@
-sphinx>=5
+sphinx>=8
 sphinx-issues
 sphinx-notfound-page>=0.5
 sphinx-rtd-theme