install julia 1.11 in python test workflow

Author: Christopher Doris

.github/workflows/tests.yml

@@ -84,6 +84,12 @@ jobs:
         uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.pyversion }}
+      
+      - name: Check Python OpenSSL version (see setup_julia)
+        shell: python
+        run: |
+          import ssl
+          assert ssl.OPENSSL_VERSION_INFO < (3, 5)
 
       - name: Set up uv
         uses: astral-sh/setup-uv@v6
@@ -94,7 +100,9 @@ jobs:
         id: setup_julia
         uses: julia-actions/setup-julia@v2
         with:
-          version: '1'
+          # Python in the GitHub runners ships with OpenSSL 3.0. Julia 1.12 requires
+          # OpenSSL 3.5. Therefore juliapkg requires Julia 1.11 or lower.
+          version: '1.11'
 
       - name: Set up test Julia project
         if: ${{ matrix.juliaexe == 'julia' }}