[clang] [clang-format] Fix path expansion inside git-clang-format.bat (PR #114078)

[Owen Pan via cfe-commits]

================
@@ -1 +1 @@
-py -3 "%~pn0" %*
+py -3 "%~dpn0" %*
----------------
owenca wrote:

```suggestion
py -3 "%~f0" %*
```
See https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/call#batch-parameters.

https://github.com/llvm/llvm-project/pull/114078