Set macOS deployment target to 10.13

[eiskrenkov]

Hey! Fist of all, thank you for the tool!

There's an issue with it though, it's impossible to build it on macOS sequoia, here's an error:

==> Installing xcodeproj-format from odnoletkov/tap
==> xcodebuild install SYMROOT=build DSTROOT=/ INSTALL_PATH=/opt/homebrew/Cellar/xcodeproj-format/0.1/bin
Last 15 lines from /Users/eiskrenkov/Library/Logs/Homebrew/xcodeproj-format/01.xcodebuild:

command: P0:::CreateBuildDirectory /tmp/xcodeproj-format-20241023-43519-rxohn5/build ->

CYCLE POINT ->

node: / ->

directoryTreeSignature:  ->

directoryContents: / ->

node: /
/tmp/xcodeproj-format-20241023-43519-rxohn5/xcodeproj-format.xcodeproj: warning: The macOS deployment target 'MACOSX_DEPLOYMENT_TARGET' is set to 10.8, but the range of supported deployment target versions is 10.13 to 15.0.99. (in target 'xcodeproj-format' from project 'xcodeproj-format')
** INSTALL FAILED **


If reporting this issue please do so at (not Homebrew/brew or Homebrew/homebrew-core):
  https://github.com/odnoletkov/homebrew-tap/issues

I used 10.13 as a macOS deployment target and it seems to work! Would really appreciate it if you can merge this so that xcodeproj-format is installable via homebrew again. Thank you so much in advance!