CI: pin downgrade runtest resolution settings (#175)

Co-authored-by: Stefan Krastanov <stefan@krastanov.org>

Author: Krastanov-agent

.github/workflows/downgrade.yml

@@ -35,4 +35,7 @@ jobs:
           julia_version: ${{ matrix.version }}
       - uses: julia-actions/cache@v2
       - uses: julia-actions/julia-buildpkg@v1
-      - uses: julia-actions/julia-runtest@v1
+      - uses: julia-actions/julia-runtest@v1
+        with:
+          allow_reresolve: false
+          force_latest_compatible_version: false