[SPARK-55313][PYTHON][FOLLOW-UP] Do not auto-activate conda for CI

### What changes were proposed in this pull request?

Set `auto-activate` to `false` for conda action.

### Why are the changes needed?

After reading https://github.com/conda-incubator/setup-miniconda/blob/main/action.yml I think the previous change to `activate-environment` applies to *new* shells, which is also helpful. However, the immediate fix we need is to not activate conda environments in the *current* shell.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

CI should show (the previous fix did not fix coverage run).

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes #54120 from gaogaotiantian/fix-conda-auto-activate.

Authored-by: Tian Gao <gaogaotiantian@hotmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>

Author: gaogaotiantian

.github/workflows/build_and_test.yml

@@ -638,6 +638,7 @@ jobs:
       with:
         miniforge-version: latest
         activate-environment: ""
+        auto-activate: false
     # Run the tests.
     - name: Run tests
       env: ${{ fromJSON(inputs.envs) }}