Utils/update-checkout failure on release/5.6

Hello! I've encountered an error while building 5.6 release of Swift on my CI: LICENSE.TXT causes error while checking out repo on case-insensitive file system · Issue #5203 · apple/llvm-project · GitHub
The issue was caused by merged in license file which has the same name on case-insensitive file systems as the existing one.
Here is a pull-request deleting one of those files (they have identical content): Delete LICENSE.txt by StoneSpb · Pull Request #5204 · apple/llvm-project · GitHub
Please take a look.

https://github.com/apple/llvm-project/pull/5204#issuecomment-1233536139

Looks like @jansvoboda11 removed this in ecddb8c, so closing this PR. Please reopen if you think we missed something. Thanks!