chore: make virtualenv<21 pin conditional on Python < 3.10 (#72)

Use PEP 508 environment markers to only pin virtualenv<21 for Python
versions less than 3.10, as virtualenv 21+ dropped Python 3.8 support.

This allows Python 3.10+ to use the latest virtualenv while maintaining
compatibility with Python 3.8 and 3.9.

Signed-off-by: Jericho Tolentino <68654047+jericht@users.noreply.github.com>

Author: jericht

.github/workflows/reusable_prerelease.yml

@@ -25,7 +25,7 @@ jobs:
 
       - name: Build
         run: |
-          pip install --upgrade hatch "virtualenv<21"
+          pip install --upgrade hatch 'virtualenv<21; python_version < "3.10"'
           hatch -v build
 
       # A precommit hook into the GitHub Action workflow.

.github/workflows/reusable_publish.yml

@@ -102,7 +102,7 @@ jobs:
       # Tag must be made before building so the generated _version.py files have the correct version
       - name: Build
         run: |
-          pip install --upgrade hatch "virtualenv<21"
+          pip install --upgrade hatch 'virtualenv<21; python_version < "3.10"'
           hatch -v build
 
       # A precommit hook into the GitHub Action workflow.
@@ -210,7 +210,7 @@ jobs:
 
       - name: Install dependencies
         run: |
-          pip install --upgrade hatch "virtualenv<21"
+          pip install --upgrade hatch 'virtualenv<21; python_version < "3.10"'
           pip install --upgrade twine
 
       - name: Build

.github/workflows/reusable_publish_v2.yml

@@ -103,7 +103,7 @@ jobs:
 
       - name: Build
         run: |
-          pip install --upgrade hatch "virtualenv<21"
+          pip install --upgrade hatch 'virtualenv<21; python_version < "3.10"'
           hatch -v build
 
       # A precommit hook into the GitHub Action workflow.
@@ -308,7 +308,7 @@ jobs:
 
       - name: Install dependencies
         run: |
-          pip install --upgrade hatch "virtualenv<21"
+          pip install --upgrade hatch 'virtualenv<21; python_version < "3.10"'
           pip install --upgrade twine
 
       - name: Download

.github/workflows/reusable_python_build.yml

@@ -65,7 +65,7 @@ jobs:
 
     - name: Install Hatch
       run: |
-        pip install --upgrade hatch "virtualenv<21"
+        pip install --upgrade hatch 'virtualenv<21; python_version < "3.10"'
 
     - name: Run Linting
       run: hatch -v run lint