Bump io.netty:netty-bom from 4.1.90.Final to 4.1.91.Final (#5346)

Bumps [io.netty:netty-bom](https://github.com/netty/netty) from 4.1.90.Final to 4.1.91.Final.
- [Release notes](https://github.com/netty/netty/releases)
- [Commits](netty/netty@netty-4.1.90.Final...netty-4.1.91.Final)

---
updated-dependencies:
- dependency-name: io.netty:netty-bom
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

dependencyManagement/build.gradle.kts

@@ -19,7 +19,7 @@ val DEPENDENCY_BOMS = listOf(
   "com.squareup.okhttp3:okhttp-bom:4.10.0",
   "com.squareup.okio:okio-bom:3.3.0", // applies to transitive dependencies of okhttp
   "io.grpc:grpc-bom:1.54.0",
-  "io.netty:netty-bom:4.1.90.Final",
+  "io.netty:netty-bom:4.1.91.Final",
   "io.zipkin.brave:brave-bom:5.15.0",
   "io.zipkin.reporter2:zipkin-reporter-bom:2.16.3",
   "org.assertj:assertj-bom:3.24.2",