T7037: Add prebuild command for the package-build

Add pre_build_cmd for the package build after clonning a repo
but before apply patches

scripts/package-build/build.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2024 VyOS maintainers and contributors
+# Copyright (C) 2024-2025 VyOS maintainers and contributors
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 or later as
@@ -92,6 +92,17 @@ def build_package(package: list, patch_dir: Path) -> None:
         # Check out the specific commit
         run(['git', 'checkout', package['commit_id']], cwd=repo_dir, check=True)
 
+        # Pre build command
+        pre_build_cmd = package.get('pre_build_cmd', '')
+        if pre_build_cmd:
+            try:
+                print(f'I: execute pre_build_cmd for the package {repo_name}')
+                run(pre_build_cmd, cwd=repo_dir, check=True, shell=True)
+            except CalledProcessError as e:
+                print(e)
+                print(f"I: Pre build command failed for the {repo_name}")
+                raise
+
         # Apply patches if any
         if (repo_dir / 'patches'):
             apply_patches(repo_dir, patch_dir / repo_name)