ci: pin os version to avoid unexpected breakage of ci

As of this writing, we had failure due to an osx image update:
 * https://github.com/actions/setup-python/issues/852

And in the past I have seen the same for Ubuntu images.
 * bqplot/bqplot#1588 (comment)

.github/workflows/check-release.yml

@@ -7,7 +7,7 @@ on:
 
 jobs:
   check_release:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     strategy:
       matrix:
         group: [check_release, link_check]

.github/workflows/docs.yml

@@ -6,11 +6,11 @@ on:
     branches: '*'
 jobs:
   build:
-    runs-on: ${{ matrix.os }}-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu]
+        os: [ubuntu-22.04]
         python-version: [ '3.7' ]
     steps:
     - name: Checkout

.github/workflows/downstream.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   downstream:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     timeout-minutes: 15
 
     steps:

.github/workflows/enforce-label.yml

@@ -5,7 +5,7 @@ on:
     types: [labeled, unlabeled, opened, edited, synchronize]
 jobs:
   enforce-label:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: enforce-triage-label
         uses: jupyterlab/maintainer-tools/.github/actions/enforce-label@v1

.github/workflows/js.yml

@@ -8,19 +8,19 @@ on:
 
 jobs:
   build:
-    runs-on: ${{ matrix.os }}-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu, macos]
+        os: [ubuntu-22.04, macos-12.0]
         group: [notebook, base, services]
         exclude:
           - group: services
     steps:
       - name: Checkout
         uses: actions/checkout@v2
       - name: Set up Python
-        uses: actions/setup-python@v1
+        uses: actions/setup-python@v5
         with:
           python-version: 3.8
       - name: Set up Node

.github/workflows/playwright.yml

@@ -7,18 +7,18 @@ on:
     branches: '*'
 jobs:
   build:
-    runs-on: ${{ matrix.os }}-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu, macos]
+        os: [ubuntu-22.04, macos-12.0]
         python-version: [ '3.7', '3.8', '3.9', '3.10']
     steps:
     - name: Checkout
       uses: actions/checkout@v2
 
     - name: Set up Python
-      uses: actions/setup-python@v1
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
 

.github/workflows/pythonpackage.yml

@@ -8,11 +8,11 @@ on:
 
 jobs:
   build:
-    runs-on: ${{ matrix.os }}-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu, macos, windows]
+        os: [ubuntu-22.04, macos-12.0, windows-2022]
         python-version: ["3.7", "3.8", "3.9", "3.10", "pypy-3.8"]
         exclude:
           - os: windows