[CI] Modify test requirements and CI workflow (#578)

* [CI] Modify test requirements and CI workflow

- Replaced `flash-attn` with `packaging` and `wheel` in `requirements-test.txt` to ensure proper package management.
- Updated the CI workflow to install `flash-attn` without build isolation, improving the installation process.

* [CI] remove redundant packages

* [CI] Update test requirements and CI workflow

- Added `flash-attn` to `requirements-test.txt` to ensure it is included in the testing environment.
- Modified the CI workflow to install packages from `requirements-test.txt` with `PIP_NO_BUILD_ISOLATION=1`, improving the installation process.

.github/workflows/ci.yml

@@ -56,7 +56,7 @@ jobs:
       run: |
         source tilelang_ci/bin/activate
         python -m pip install --upgrade pip
-        if [ -f requirements-test.txt ]; then python -m pip install -r requirements-test.txt; fi
+        if [ -f requirements-test.txt ]; then PIP_NO_BUILD_ISOLATION=1 python -m pip install -r requirements-test.txt; fi
 
     - name: Install project in wheel mode
       run: |