Update ci.yml: run CI and docs on v1.11

Author: dkarrasch

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - 'nightly'
+          - '1.11'
         os:
           - ubuntu-latest
           - macOS-latest
@@ -68,7 +68,7 @@ jobs:
       - uses: julia-actions/setup-julia@latest
         with:
           # version: '1.6'
-          version: 'nightly'
+          version: '1.11'
       - name: Generate docs
         run: |
           julia --color=yes -e 'write("Project.toml", replace(read("Project.toml", String), r"uuid = .*?\n" =>"uuid = \"3f01184e-e22b-5df5-ae63-d93ebab69eaf\"\n"));'