Skip ambient for test-dist on Python 3.14

Reasoning in comment. Note that Python 3.14 is still tested for other
runtimes.

Author: victorlin

.github/workflows/ci.yaml

@@ -271,6 +271,9 @@ jobs:
       - uses: ./src/.github/actions/setup-integration-tests
         with:
           python-version: ${{ matrix.python }}
+          # Snakemake is not yet compatible with Python 3.14.
+          # <https://github.com/snakemake/snakemake/pull/3739>
+          ambient: ${{ matrix.python != '3.14' }}
 
       - uses: actions/download-artifact@v8
         with:
@@ -281,6 +284,8 @@ jobs:
         run: python3 -m pip install --upgrade dist/nextstrain_cli-*-py3-none-any.whl
 
       - uses: ./src/.github/actions/run-integration-tests
+        with:
+          ambient: ${{ matrix.python != '3.14' }}
 
   test-standalone:
     needs: build-standalone