wrap: Don't use patch.exe from Strawberry Perl

It barfs on patches from git-format-patch:

```
Applying diff file "orc-0.4.38\0001-meson-fix-symbols-leaking-from-static-library-on-Win.patch"
patching file meson.build
Assertation failed!
Program: C:\Strawberry\c\bin\patch.EXE
File: .\src\patch\2.5.9\patch-2.5.9-src\patch.c, Line 354
Expression: hunk
```

Author: nirbheek

mesonbuild/wrap/wrap.py

@@ -57,7 +57,13 @@
 
 ALL_TYPES = ['file', 'git', 'hg', 'svn', 'redirect']
 
-PATCH = shutil.which('patch')
+if mesonlib.is_windows():
+    from ..programs import ExternalProgram
+    _patch = ExternalProgram('patch', exclude_paths=[r'C:\Strawberry\c\bin'])
+    PATCH = _patch.get_path() if _patch.found() else None
+else:
+    PATCH = shutil.which('patch')
+
 
 def whitelist_wrapdb(urlstr: str) -> urllib.parse.ParseResult:
     """ raises WrapException if not whitelisted subdomain """