Bump gap-actions/run-pkg-tests from 2 to 3

Bumps [gap-actions/run-pkg-tests](https://github.com/gap-actions/run-pkg-tests) from 2 to 3.
- [Commits](gap-actions/run-pkg-tests@v2...v3)

---
updated-dependencies:
- dependency-name: gap-actions/run-pkg-tests
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/gap.yml

@@ -29,7 +29,7 @@ jobs:
         with:
           GAPBRANCH: ${{ matrix.gap-branch }}
       - name: "Run DigraphsTestInstall"
-        uses: gap-actions/run-pkg-tests@v2
+        uses: gap-actions/run-pkg-tests@v3
         with:
           GAP_TESTFILE: "tst/testall.g"
       - uses: gap-actions/process-coverage@v2