Update .github/workflows/ci.yaml

Author: OskarStark

.github/workflows/ci.yaml

@@ -75,7 +75,7 @@ jobs:
             -   name: "Run DOCtor-RST"
                 uses: docker://oskarstark/doctor-rst:1.47.1
                 with:
-                    args: --short --error-format=github
+                    args: --short --error-format=github --cache-file=/github/workspace/.cache/doctor-rst.cache
 
     symfony-code-block-checker:
         name: Code Blocks