dependencies: update llvm versions

15 is the current snapshot version, 13 and 14 are released.

mesonbuild/environment.py

@@ -159,6 +159,8 @@ def get_llvm_tool_names(tool: str) -> T.List[str]:
     # unless it becomes a stable release.
     suffixes = [
         '', # base (no suffix)
+        '-14',  '14',
+        '-13',  '13',
         '-12',  '12',
         '-11',  '11',
         '-10',  '10',
@@ -173,7 +175,7 @@ def get_llvm_tool_names(tool: str) -> T.List[str]:
         '-3.7', '37',
         '-3.6', '36',
         '-3.5', '35',
-        '-13',    # Debian development snapshot
+        '-15',    # Debian development snapshot
         '-devel', # FreeBSD development snapshot
     ]
     names = []