dev-python/mypy: remove unused patch.

Closes: https://github.com/gentoo/gentoo/pull/2326

Signed-off-by: Patrice Clement <monsieurp@gentoo.org>

dev-python/mypy/files/use-which.patch

@@ -1,20 +0,0 @@
-diff --git a/scripts/mypy b/scripts/mypy
-index e758f1f..5a06146 100755
---- a/scripts/mypy
-+++ b/scripts/mypy
-@@ -45,14 +45,7 @@ def find_bin_directory() -> str:
- 
-     This is used by build to find stubs and other data files.
-     """
--    script = __file__
--    # Follow up to 5 symbolic links (cap to avoid cycles).
--    for i in range(5):
--        if os.path.islink(script):
--            script = readlinkabs(script)
--        else:
--            break
--    return os.path.dirname(script)
-+    return os.path.dirname(shutil.which('mypy'))
- 
- 
- def readlinkabs(link: str) -> str: