Update dependency ubuntu to v22

Author: renovate[bot]

.github/workflows/check-renovatebot-config.yml

@@ -7,7 +7,7 @@ on:
 jobs:
   validate:
     name: Validate renovatebot config
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout
         uses: actions/checkout@v3

.github/workflows/doctoc.yml

@@ -8,7 +8,7 @@ on:
 jobs:
   verify-doctoc:
     name: Verifies whether table of contents has been updated
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     steps:
       - name: Checkout code

.github/workflows/test-extract-metadata-action.yml

@@ -8,7 +8,7 @@ on:
 jobs:
   test-extract-metadata:
     name: Retrieves metadata
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     steps:
       - name: Check that environment is empty

.github/workflows/test-healthcheck-action.yml

@@ -8,7 +8,7 @@ on:
 jobs:
   test-healthcheck-success:
     name: Verifies whether healthcheck action succeeds when it should
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     steps:
       - name: Checkout code

.github/workflows/test-setup-e2e-environment-action.yml

@@ -7,7 +7,7 @@ on:
 
 jobs:
   test-e2e-setup-action:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     strategy:
       matrix: