chore(deps): update swift docker tag to v6

Author: renovate[bot]

.devcontainer/devcontainer.json

@@ -1,6 +1,6 @@
 {
   "name": "Swift 5.6",
-  "image": "swift:5.6-focal",
+  "image": "swift:6.1-focal",
   "extensions": [
     "sswg.swift-lang"
   ],

.github/workflows/merge-main.yml

@@ -12,7 +12,7 @@ on:
 jobs:
   prepare:
     name: Calculate Version and Build number
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-20.04
 
     outputs:
       build_number: ${{ steps.short_sha.outputs.value }}
@@ -42,7 +42,7 @@ jobs:
     if: needs.prepare.outputs.new_release == 'true'
 
     name: Dev and Draft Releases
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-20.04
 
     needs:
     - prepare

.github/workflows/pull-request.yml

@@ -15,7 +15,7 @@ on:
 jobs:
   validate:
     name: Validate
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-20.04
 
     steps:
     - uses: actions/checkout@v4