Update GitHub actions (#88)

* build_trio.yml: Build on macos-15 and Xcode 16

macos-15 is currently in public beta, but verified to build Trio-dev succesfully

More info:
https://github.com/actions/runner-images/blob/main/images/macos/macos-15-arm64-Readme.md

* Run all macOS jobs on macos-15 and Xcode 16.0

* GH actions: Remove xcode-select where not needed

.github/workflows/add_identifiers.yml

@@ -12,11 +12,8 @@ jobs:
   identifiers:
     name: Add Identifiers
     needs: validate
-    runs-on: macos-14
+    runs-on: macos-15
     steps:
-      # Uncomment to manually select latest Xcode if needed
-      #- name: Select Latest Xcode
-      #  run: "sudo xcode-select --switch /Applications/Xcode_13.0.app/Contents/Developer"
 
       # Checks-out the repo
       - name: Checkout Repo

.github/workflows/build_trio.yml

@@ -186,7 +186,7 @@ jobs:
   build:
     name: Build
     needs: [validate, check_alive_and_permissions, check_latest_from_upstream]
-    runs-on: macos-14
+    runs-on: macos-15
     permissions:
       contents: write
     if:
@@ -198,7 +198,7 @@ jobs:
       )
     steps:
       - name: Select Xcode version
-        run: "sudo xcode-select --switch /Applications/Xcode_15.4.app/Contents/Developer"
+        run: "sudo xcode-select --switch /Applications/Xcode_16.0.app/Contents/Developer"
       
       - name: Checkout Repo for syncing
         if: |

.github/workflows/create_certs.yml

@@ -12,11 +12,8 @@ jobs:
   certificates:
     name: Create Certificates
     needs: validate
-    runs-on: macos-14
+    runs-on: macos-15
     steps:
-      # Uncomment to manually select latest Xcode if needed
-      #- name: Select Latest Xcode
-      #  run: "sudo xcode-select --switch /Applications/Xcode_13.0.app/Contents/Developer"
 
       # Checks-out the repo
       - name: Checkout Repo

.github/workflows/validate_secrets.yml

@@ -5,7 +5,7 @@ on: [workflow_call, workflow_dispatch]
 jobs:
   validate-access-token:
     name: Access
-    runs-on: macos-14
+    runs-on: macos-15
     env:
       GH_PAT: ${{ secrets.GH_PAT }}
       GH_TOKEN: ${{ secrets.GH_PAT }}
@@ -74,7 +74,7 @@ jobs:
   validate-match-secrets:
     name: Match-Secrets
     needs: validate-access-token
-    runs-on: macos-14
+    runs-on: macos-15
     env:
       GH_TOKEN: ${{ secrets.GH_PAT }}
     steps:
@@ -112,7 +112,7 @@ jobs:
   validate-fastlane-secrets:
     name: Fastlane
     needs: [validate-access-token, validate-match-secrets]
-    runs-on: macos-14
+    runs-on: macos-15
     env:
       GH_PAT: ${{ secrets.GH_PAT }}
       GH_TOKEN: ${{ secrets.GH_PAT }}