ci: limit virtualenv version

Author: G-Rath

.github/workflows/ci.yml

@@ -54,7 +54,7 @@ jobs:
       - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version-file: '.python-version'
-      - run: pipx install poetry~=2.0
+      - run: pipx install poetry~=2.0 virtualenv<=20.32.0
       - run: poetry install
       - run: poetry run mypy .
   pytest:
@@ -69,7 +69,7 @@ jobs:
       - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version-file: '.python-version'
-      - run: pipx install poetry~=2.0
+      - run: pipx install poetry~=2.0 virtualenv<=20.32.0
       - run: poetry install
       - run: poetry run pytest
   validate:
@@ -84,7 +84,7 @@ jobs:
       - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version-file: '.python-version'
-      - run: pipx install poetry~=2.0
+      - run: pipx install poetry~=2.0 virtualenv<=20.32.0
       - run: poetry install
       - run: poetry run scripts/validate_advisories.py
   prettier: