build(deps): bump swagger-parser.version from 2.1.20 to 2.1.21 (#628)

Bumps `swagger-parser.version` from 2.1.20 to 2.1.21.

Updates `io.swagger.parser.v3:swagger-parser-v3` from 2.1.20 to 2.1.21

Updates `io.swagger.parser.v3:swagger-parser` from 2.1.20 to 2.1.21
- [Release notes](https://github.com/swagger-api/swagger-parser/releases)
- [Commits](swagger-api/swagger-parser@v2.1.20...v2.1.21)

Updates `io.swagger.parser.v3:swagger-parser-v2-converter` from 2.1.20 to 2.1.21

---
updated-dependencies:
- dependency-name: io.swagger.parser.v3:swagger-parser-v3
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: io.swagger.parser.v3:swagger-parser
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: io.swagger.parser.v3:swagger-parser-v2-converter
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

pom.xml

@@ -83,7 +83,7 @@
         <sonar.host.url>https://sonarcloud.io</sonar.host.url>
         <sonar.moduleKey>${project.artifactId}</sonar.moduleKey>
 
-        <swagger-parser.version>2.1.20</swagger-parser.version>
+        <swagger-parser.version>2.1.21</swagger-parser.version>
         <slf4j.version>2.0.12</slf4j.version>
     </properties>