ci: run downgrade CI only for LTS

Author: ven-k

.github/workflows/Downgrade.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        version: ['1', 'lts']
+        version: ['lts']
     steps:
       - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v2