Use latest Ubuntu (LTS) image consistenly across GitHub workflow

.github/workflows/build.yaml

@@ -12,7 +12,7 @@ env:
 jobs:
 
   build-webui:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
 
     steps:
       - name: Check out code
@@ -35,7 +35,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ ubuntu-22.04, macos-latest, windows-latest ]
+        os: [ ubuntu-latest, macos-latest, windows-latest ]
     needs:
       - build-webui
 

.github/workflows/check_doc.yml

@@ -9,7 +9,7 @@ jobs:
 
   docs:
     name: Check, verify and build documentation
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
 
     steps:
       - name: Check out code

.github/workflows/documentation.yml

@@ -14,7 +14,7 @@ jobs:
 
   docs:
     name: Doc Process
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     if: github.repository == 'traefik/traefik'
 
     steps:

.github/workflows/experimental.yaml

@@ -15,7 +15,7 @@ jobs:
   experimental:
     if: github.repository == 'traefik/traefik'
     name: Build experimental image on branch
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
 
     steps:
 

.github/workflows/test-integration.yaml

@@ -15,7 +15,7 @@ env:
 jobs:
 
   build:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
 
     steps:
       - name: Check out code
@@ -35,7 +35,7 @@ jobs:
         run: make binary
 
   test-integration:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     needs:
       - build
     strategy:

.github/workflows/test-unit.yaml

@@ -11,7 +11,7 @@ env:
 jobs:
 
   test-unit:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
 
     steps:
       - name: Check out code

.github/workflows/validate.yaml

@@ -13,7 +13,7 @@ env:
 jobs:
 
   validate:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
 
     steps:
       - name: Check out code
@@ -39,7 +39,7 @@ jobs:
         run: make validate
 
   validate-generate:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
 
     steps:
       - name: Check out code