DOCS: pin mkdocs version

Signed-off-by: jokob-sk <jokob.sk@gmail.com>

.github/workflows/mkdocs.yml

@@ -22,8 +22,10 @@ jobs:
 
       - name: Install MkDocs
         run: |
-          pip install mkdocs mkdocs-material
-          pip install mkdocs-github-admonitions-plugin
+          pip install \
+            mkdocs==1.6.0 \
+            mkdocs-material==9.5.21 \
+            mkdocs-github-admonitions-plugin==0.0.4
 
       - name: Build MkDocs
         run: mkdocs build