Use major version refs of GitHub Actions actions

Use of the major version ref will cause the workflow to benefit from ongoing development to the actions up until such
time as a new major release of an action is made, at which time we would need to evaluate whether any changes to the
workflow are required by the breaking change that triggered the major release before updating the major ref
(e.g., `uses: arduino/compile-sketches@v2`).

Author: per1234

.github/workflows/compile-examples.yml

@@ -56,7 +56,7 @@ jobs:
         run: pip3 install pyserial
 
       - name: Compile examples
-        uses: arduino/compile-sketches@main
+        uses: arduino/compile-sketches@v1
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           platforms: ${{ matrix.platforms }}

.github/workflows/report-size-deltas.yml

@@ -15,7 +15,7 @@ jobs:
     steps:
       # See: https://github.com/arduino/actions/blob/master/libraries/report-size-deltas/README.md
       - name: Comment size deltas reports to PRs
-        uses: arduino/report-size-deltas@main
+        uses: arduino/report-size-deltas@v1
         with:
           # The name of the workflow artifact created by the "Compile Examples" workflow
           sketches-reports-source: sketches-reports

.github/workflows/spell-check.yml

@@ -21,4 +21,4 @@ jobs:
 
       # See: https://github.com/codespell-project/actions-codespell/blob/master/README.md
       - name: Spell check
-        uses: codespell-project/actions-codespell@master
+        uses: codespell-project/actions-codespell@v1