Merge pull request #5533 from martin-frbg/azure-osxgcc

AzureCI: Update the obsolete OSX x86_64 gcc12 job to gcc15

Author: martin-frbg

azure-pipelines.yml

@@ -171,13 +171,13 @@ jobs:
       brew update
       make USE_THREADS=0 CC=gcc-13 FC=gfortran-13
      
-- job: OSX_GCC12
+- job: OSX_GCC15
   pool:
      vmImage: 'macOS-latest'
   steps:   
   - script: |
       brew update
-      make CC=gcc-12 FC=gfortran-12
+      make CC=gcc-15 FC=gfortran-15
 
 - job: OSX_LLVM_flangnew
   pool: