Fix bug with excluding files by linter

[joshski]

Problem

When excluding files from specific linters, globs that are relative to the application root directory do not exclude files matching the glob. For example, the following snippet from the readme:

---
linters:
  DeprecatedClasses:
    enabled: true
    exclude:
      - 'app/views/shared/deprecated/**'

...would not actually exclude the DeprecatedClasses linter for any views under app/views/shared/deprecated/**

I have reproduced this bug in a separate git repository as follows.

The following commit joshski/erblint-exclude-bug-demo@6477573

• adds erb_lint to a new rails 7 app
• violates the ErbSafety lint rule.
• includes a script to reproduce the bug.

The subsequent commit in the same repo demonstrates the bug is fixed, using the revision of erb_lint proposed by this PR.

joshski/erblint-exclude-bug-demo@bcace06

Solution

When the ErbLint::Runner rejects linters for a given processed source file, match against exclusion globs using a filename relative to the base_path of the ERBLint::FileLoader.