Bump feign.version from 12.4 to 13.6

Bumps `feign.version` from 12.4 to 13.6.

Updates `io.github.openfeign:feign-core` from 12.4 to 13.6
- [Release notes](https://github.com/openfeign/feign/releases)
- [Changelog](https://github.com/OpenFeign/feign/blob/master/CHANGELOG.md)
- [Commits](OpenFeign/feign@12.4...13.6)

Updates `io.github.openfeign:feign-jackson` from 12.4 to 13.6
- [Release notes](https://github.com/openfeign/feign/releases)
- [Changelog](https://github.com/OpenFeign/feign/blob/master/CHANGELOG.md)
- [Commits](OpenFeign/feign@12.4...13.6)

Updates `io.github.openfeign:feign-slf4j` from 12.4 to 13.6
- [Release notes](https://github.com/openfeign/feign/releases)
- [Changelog](https://github.com/OpenFeign/feign/blob/master/CHANGELOG.md)
- [Commits](OpenFeign/feign@12.4...13.6)

---
updated-dependencies:
- dependency-name: io.github.openfeign:feign-core
  dependency-version: '13.6'
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: io.github.openfeign:feign-jackson
  dependency-version: '13.6'
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: io.github.openfeign:feign-slf4j
  dependency-version: '13.6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

pom.xml

@@ -96,7 +96,7 @@
     <!-- https://github.com/openapi-tools/jackson-dataformat-hal/blob/v1.0.9/pom.xml -->
     <jackson-dataformat-hal.version>1.0.9</jackson-dataformat-hal.version>
 
-    <feign.version>12.4</feign.version>
+    <feign.version>13.6</feign.version>
     <feign-form.version>3.8.0</feign-form.version>
 
   </properties>