build: bump swagger dependency and refactor

[ndr-brt]

What this PR changes/adds

Bump the injected swagger-jaxrs2-jakarta dependency version.
Cleaned up things a little, removed the gradle-swagger-generator-plugin that was not used anymore

Why it does that

Briefly state why the change was necessary.

Further notes

• it would be great to have a way to get that version number from the catalog so dependabot can take care of updating it.

[github-actions]

Test Results

39 tests  ±0   39 ✔️ ±0   22s ⏱️ -2s
10 suites ±0     0 💤 ±0 
10 files   ±0     0 ❌ ±0 

Results for commit 4c5029f. ± Comparison against base commit 39a5c5c.

This pull request removes 3 and adds 3 tests. Note that renamed tests count towards both.

org.eclipse.edc.plugins.edcbuild.conventions.SwaggerGeneratorConventionTest ‑ apply_whenApiGroupNotSpecified_shouldUseDefault()
org.eclipse.edc.plugins.edcbuild.conventions.SwaggerGeneratorConventionTest ‑ apply_whenApiGroupSpecified_shouldAppend()
org.eclipse.edc.plugins.edcbuild.conventions.SwaggerGeneratorConventionTest ‑ apply_whenOutputDirSet_shouldAppend()

org.eclipse.edc.plugins.edcbuild.conventions.SwaggerResolveConventionTest ‑ apply_whenApiGroupNotSpecified_shouldUseDefault()
org.eclipse.edc.plugins.edcbuild.conventions.SwaggerResolveConventionTest ‑ apply_whenApiGroupSpecified_shouldAppend()
org.eclipse.edc.plugins.edcbuild.conventions.SwaggerResolveConventionTest ‑ apply_whenOutputDirSet_shouldAppend()

♻️ This comment has been updated with latest results.