Use GITHUB_OUTPUT envvar instead of set-output command

Author: Belval

.github/workflows/documentation.yml

@@ -30,7 +30,7 @@ jobs:
       # Cache dependencies
       - name: Get pip cache dir
         id: pip-cache
-        run: echo "::set-output name=dir::$(pip cache dir)"
+        run: echo "dir=$(pip cache dir)" >> "$GITHUB_OUTPUT"
 
       - name: Cache dependencies
         uses: actions/cache@v2

.github/workflows/tests.yml

@@ -28,7 +28,7 @@ jobs:
       # Cache dependencies
       - name: Get pip cache dir
         id: pip-cache
-        run: echo "::set-output name=dir::$(pip cache dir)"
+        run: echo "dir=$(pip cache dir)" >> "$GITHUB_OUTPUT"
 
       - name: Cache dependencies
         uses: actions/cache@v2