github: Update GitHub-provided actions so they don't use deprecated Node.js 12

.github/workflows/tkm.yml

@@ -27,8 +27,8 @@ jobs:
     env:
       TEST: tkm
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/cache@v2
+      - uses: actions/checkout@v3
+      - uses: actions/cache@v3
         with:
           path: ${{ env.CCACHE_DIR }}
           key: ccache-tkm-${{ github.sha }}