CI: pin actions by SHA

This eliminates the possibility of a tag being changed under
us.

Author: tacaswell

.github/.github/workflows/lighthouse.yml

@@ -22,7 +22,7 @@ jobs:
           make html
 
       - name: Run Lighthouse against example docs build
-        uses: treosh/lighthouse-ci-action@v2
+        uses: treosh/lighthouse-ci-action@005e1277a8a17ea0b0ef6c3332d59a7cd0f730ce # v2
         with:
           configPath: "./lighthouserc.json"
           temporaryPublicStorage: true

.github/.github/workflows/pre-commit.yaml

@@ -13,4 +13,4 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v2
-      - uses: pre-commit/[email protected]
+      - uses: pre-commit/action@0764670bf370aab253130d534e1eda7ff497dc60 # v2.0.0