.github: bump action versions, node12 deprecated

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

.github/workflows/coverity.yml

@@ -15,7 +15,7 @@ jobs:
   coverity:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Fetch latest Coverity Scan MD5
         id: var
         env:
@@ -27,7 +27,7 @@ jobs:
           export MD5=$(cat coverity-latest.tar.gz.md5)
           echo "Got MD5 $MD5"
           echo ::set-output name=md5::${MD5}
-      - uses: actions/cache@v2
+      - uses: actions/cache@v3
         id: cache
         with:
           path: coverity-latest.tar.gz
@@ -76,7 +76,7 @@ jobs:
             --form description="${PROJECT_NAME} $(git rev-parse HEAD)" \
             https://scan.coverity.com/builds?project=${COVERITY_PROJ}
       - name: Upload build.log
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v3
         with:
           name: coverity-build.log
           path: cov-int/build-log.txt