[Security] Bump doorkeeper from 5.3.1 to 5.3.2 (#13613)

Bumps [doorkeeper](https://github.com/doorkeeper-gem/doorkeeper) from 5.3.1 to 5.3.2. **This update includes a security fix.**
- [Release notes](https://github.com/doorkeeper-gem/doorkeeper/releases)
- [Changelog](https://github.com/doorkeeper-gem/doorkeeper/blob/master/CHANGELOG.md)
- [Commits](https://github.com/doorkeeper-gem/doorkeeper/compare/v.5.3.1...v5.3.2)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Gemfile.lock

@@ -194,7 +194,7 @@ GEM
     docile (1.3.2)
     domain_name (0.5.20190701)
       unf (>= 0.0.5, < 1.0.0)
-    doorkeeper (5.3.1)
+    doorkeeper (5.3.2)
       railties (>= 5)
     dotenv (2.7.5)
     dotenv-rails (2.7.5)