Invalidation check on a stable version (#309)

Instead of testing on nightly, which can be unstable, test on a stable julia version.

Author: jishnub

.github/workflows/invalidations.yml

@@ -7,7 +7,7 @@ jobs:
     steps:
     - uses: julia-actions/setup-julia@v1
       with:
-        version: 'nightly'
+        version: '1'
     - uses: actions/checkout@v2
     - uses: julia-actions/julia-buildpkg@latest
     - uses: julia-actions/julia-invalidations@v1