Pin workflows to full-length commit SHAs

Author: giordano

.github/workflows/BuildJOSSPaper.yml

@@ -17,15 +17,15 @@ jobs:
     name: Build Paper
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Build draft PDF
         uses: openjournals/openjournals-draft-action@85a18372e48f551d8af9ddb7a747de685fbbb01c
         with:
           journal: joss
           # This should be the path to the paper within your repo.
           paper-path: paper/paper.md
       - name: Upload
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
         id: upload-paper
         with:
           name: paper