Removed pinning of virtualenv (#1501)

Author: JohanMabille

.github/workflows/ci.yml

@@ -61,7 +61,7 @@ jobs:
       - name: Install hatch
         run: |
           python --version
-          python -m pip install hatch "virtualenv<21"
+          python -m pip install hatch
 
       - name: Run the tests
         timeout-minutes: 15
@@ -105,11 +105,6 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
-      - name: Preinstall hatch and virtualenv
-        run: |
-          python --version
-          python -m pip install hatch "virtualenv<21"
-
       - uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
       - name: Run Linters
         run: |
@@ -123,11 +118,6 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
-      - name: Preinstall hatch and virtualenv
-        run: |
-          python --version
-          python -m pip install hatch "virtualenv<21"
-
       - uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
 
       - uses: jupyter-server/jupyter_releaser/.github/actions/check-release@v2
@@ -139,11 +129,6 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
-      - name: Preinstall hatch and virtualenv
-        run: |
-          python --version
-          python -m pip install hatch "virtualenv<21"
-
       - uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
 
       - name: Build API docs
@@ -168,11 +153,6 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v6
 
-      - name: Preinstall hatch and virtualenv
-        run: |
-          python --version
-          python -m pip install hatch "virtualenv<21"
-
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
 
@@ -200,11 +180,6 @@ jobs:
         with:
           python-version: "3.10"
 
-      - name: Preinstall hatch and virtualenv
-        run: |
-          python --version
-          python -m pip install hatch "virtualenv<21"
-
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
         with:
@@ -227,11 +202,6 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v6
 
-      - name: Preinstall hatch and virtualenv
-        run: |
-          python --version
-          python -m pip install hatch "virtualenv<21"
-
       - name: Base Setup
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
         with: