Excluded files impact the performance of swiftlint

New Issue Checklist

• Updated SwiftLint to the latest version => I built it from source
• I searched for existing GitHub issues

Describe the bug

The number of files present in the working tree of swiftlint has a huge impact on its performance even if most of these files are ignored. Here's a concrete example/repro:

• Create a temporary directory with just one file to lint:

mkdir /tmp/swiftlint_tests && cd /tmp/swiftlint_tests
touch test.swift

• Use hyperfine to measure the execution time of swiftlint:

$ hyperfine --warmup 1 'swiftlint'
➜  swiftlint_tests hyperfine --warmup 1 'swiftlint'
  Time (mean ± σ):      61.4 ms ±   0.9 ms    [User: 52.2 ms, System: 7.1 ms]
  Range (min … max):    59.9 ms …  65.4 ms    46 runs

• Create a subdirectory with a lot of swift files in it, create a linter config to exclude these files:

mkdir .build
for i in {1..10000}
do
  touch .build/$i.swift
done

echo "excluded:\n  - '**/.build'" > .swiftlint.yml

• Make sure that these ignored files are actually ignored:

$ swiftlint
Linting Swift files in current working directory
Linting 'test.swift' (1/1)
Done linting! Found 0 violations, 0 serious in 1 file.

• Benchmark swiftlint again:

➜  swiftlint_tests hyperfine --warmup 1 'swiftlint'
  Time (mean ± σ):     378.7 ms ±   6.1 ms    [User: 229.2 ms, System: 377.6 ms]
  Range (min … max):   368.2 ms … 389.6 ms    10 runs

The execution time is 6x what it is when these ignored files don't exist. Using the --use-alternative-excluding flag brings this to 5x but it'd still be nice to completely ignore these file. Not using a glob pattern in the config improves things by another 1x.

It looks like the code is traversing the entire file tree in a few places (e.g. in the glob implementation), we could maybe make it use a recursive approach and stop when it encounters a subdirectory that is ignored (e.g. in my example it'd not look at the content of the .build directory at all).

Environment

• SwiftLint version (run swiftlint version to be sure)?
  From source

• Installation method used (Homebrew, CocoaPods, building from source, etc)?
  Source

• Paste your configuration file:
  See example

• Are you using nested configurations?
  No

• Which Xcode version are you using (check xcodebuild -version)?

$ xcodebuild -version
Xcode 14.3
Build version 14E222b

Start by tracing SwiftLint's file-tree traversal and glob implementation, including the path used by --use-alternative-excluding. Reproduce the hyperfine comparison with one Swift file and 10,000 excluded files, then verify that excluded directories are not fully traversed and that linting output remains unchanged.