Relative excluded path in a nested configuration is ignored

New Issue Checklist

• Updated SwiftLint to the latest version
• I searched for existing GitHub issues

Describe the bug

When a relative excluded path is present in a nested configuration it is ignored in SwiftLint 0.43.0 . If I try to run SwiftLint 0.42.0 in the same setup it works fine.
It may be related to #3557 . But that issue mentions the case without any nested configurations.

Complete output when running SwiftLint, including the stack trace and command used

❯ swiftlint version
0.43.0

~/work/test
❯ swiftlint
Linting Swift files in current working directory
Linting 'test.swift' (1/1)
/Users/asolovev/work/test/A/B/test.swift:1:1: warning: Identifier Name Violation: Variable name should be between 10 and 40 characters long: 'abcd' (identifier_name)
Done linting! Found 1 violation, 0 serious in 1 file.

~/work/test
❯ mint run swiftlint@0.42.0
Linting Swift files in current working directory
Done linting! Found 0 violations, 0 serious in 0 files.

Environment

• SwiftLint version (run swiftlint version to be sure)?
  0.43.0
• Installation method used (Homebrew, CocoaPods, building from source, etc)?
  Mint. The same happens when using mint run and when using a 0.43.0 version linked to /usr/local/bin
• Paste your configuration file:

./.swiftlint.yml

identifier_name:
  min_length: 10

./A/.swiftlint.yml

excluded:
 - B

• Are you using nested configurations?
  If so, paste their relative paths and respective contents.
  Yes.

❯ find .
.
./.swiftlint.yml
./A
./A/.swiftlint.yml
./A/B
./A/B/test.swift

Configurations are mentioned above
./A/B/test.swift

let abcd = 10

• Which Xcode version are you using (check xcodebuild -version)?
  Xcode 12.4
  Build version 12D4e
• Do you have a sample that shows the issue? Run echo "[string here]" | swiftlint lint --no-cache --use-stdin --enable-all-rules
  to quickly test if your example is really demonstrating the issue. If your example is more
  complex, you can use swiftlint lint --path [file here] --no-cache --enable-all-rules.

It is a nested configuration issue, but it can be reproduced with data I mentioned before

Reproduce the nested setup with .swiftlint.yml, A/.swiftlint.yml, A/B/test.swift, and SwiftLint 0.43.0, then compare it with 0.42.0 using the listed commands. Trace how the nested configuration resolves the relative excluded path B; done means linting A/B/test.swift reports no violations as it does in 0.42.0.