Pivot out of the repository so that we test the wheel.

Change-Id: Ie291a4c1f1e847d9ffb86112df027cc6bc2100c2
Reviewed-on: https://code-review.googlesource.com/c/re2/+/63290
Reviewed-by: Alex Chernyakhovsky <achernya@google.com>
Reviewed-by: Paul Wankadia <junyer@google.com>

.github/workflows/python.yml

@@ -61,6 +61,10 @@ jobs:
       - name: Test wheel
         run: |
           "${PYTHON}" -m pip install google_re2-*.whl
+          # Pivot out of the repository so that we test the wheel.
+          DIR=$(mktemp -d)
+          cp re2_test.py "${DIR}"
+          cd "${DIR}"
           "${PYTHON}" re2_test.py
         shell: bash
         working-directory: python
@@ -122,6 +126,10 @@ jobs:
         name: Test wheel
         run: |
           python -m pip install google_re2-*.whl
+          # Pivot out of the repository so that we test the wheel.
+          DIR=$(mktemp -d)
+          cp re2_test.py "${DIR}"
+          cd "${DIR}"
           python re2_test.py
         shell: bash
         working-directory: python
@@ -179,6 +187,10 @@ jobs:
       - name: Test wheel
         run: |
           python -m pip install google_re2-*.whl
+          # Pivot out of the repository so that we test the wheel.
+          DIR=$(mktemp -d)
+          cp re2_test.py "${DIR}"
+          cd "${DIR}"
           python re2_test.py
         shell: bash
         working-directory: python