Use explicit Ubuntu 24.04, not latest

Allows to have more conscious runner updates and avoids hard-to-find
regressions resulting from underlying runner image changes.

Author: Bromeon

.github/workflows/build-website.yml

@@ -25,7 +25,7 @@ permissions:
 
 jobs:
   check-website:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     if: github.event_name == 'pull_request'
     steps:
       - name: "Checkout"
@@ -40,7 +40,7 @@ jobs:
 
 
   deploy-website:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     if: github.event_name != 'pull_request'
     steps:
       - name: "Workflow triggered by push to master"
@@ -133,7 +133,7 @@ jobs:
   license-guard:
     # not on repo dispatch
     if: github.event_name != 'repository_dispatch'
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4
 

.github/workflows/garbage-collect.yml

@@ -18,7 +18,7 @@ defaults:
 
 jobs:
   remove-closed-prs:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     steps:
       - name: "Checkout"
         uses: actions/checkout@v4

.github/workflows/update-docs.yml

@@ -27,7 +27,7 @@ defaults:
 
 jobs:
   update-docs:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     steps:
 #      - name: "Info about workflow (${{ github.event.client_payload.op }} ${{ github.event.client_payload.repo }}/${{ github.event.client_payload.num }})"
       - name: "Info about workflow (${{ env.OP }} ${{ env.REPO }}/${{ env.NUM }})"