Update .github/workflows/ci.yml

Co-authored-by: Max Horn <max@quendi.de>

Author: mortenpi

.github/workflows/ci.yml

@@ -30,7 +30,7 @@ jobs:
           arch: ${{ matrix.arch }}
           show-versioninfo: true
       - uses: julia-actions/cache@v2
-      - uses: julia-actions/julia-runtest@latest
+      - uses: julia-actions/julia-runtest@v1
       - uses: julia-actions/julia-processcoverage@v1
       - uses: codecov/codecov-action@v1
         with: