deps: Bump kafka_source (+kafka_server_binary) -> 3.9.1

[dependency-envoy]

Resolve a couple of CVEs (CVE-2025-27817, CVE-2025-27818) that most likely dont affect us but are showing up in our scanner

Signed-off-by: dependency-envoy[bot] <148525496+dependency-envoy[bot]@users.noreply.github.com>

[repokitteh-read-only]

CC @envoyproxy/dependency-shepherds: Your approval is needed for changes made to (bazel/.*repos.*\.bzl)|(bazel/dependency_imports\.bzl)|(api/bazel/.*\.bzl)|(.*/requirements\.txt)|(.*\.patch).
envoyproxy/dependency-shepherds assignee is @RyanTheOptimist

🐱

Caused by: #41287 was opened by dependency-envoy[bot].

see: more, trace.

[phlax]

cc @adamkotwasinski seems like even trying to bump to this version is throwing errors

 In file included from contrib/kafka/filters/network/source/mesh/command_handlers/produce.cc:3:
bazel-out/k8-opt/bin/contrib/kafka/filters/network/source/external/responses.h:15367:8: error: redefinition of 'Listener'
 15367 | struct Listener {
       |        ^
bazel-out/k8-opt/bin/contrib/kafka/filters/network/source/external/requests.h:17834:8: note: previous definition is here
 17834 | struct Listener {
       |        ^
In file included from contrib/kafka/filters/network/source/mesh/command_handlers/produce.cc:3:
bazel-out/k8-opt/bin/contrib/kafka/filters/network/source/external/responses.h:19287:8: error: redefinition of 'StateBatch'
 19287 | struct StateBatch {
       |        ^
bazel-out/k8-opt/bin/contrib/kafka/filters/network/source/external/requests.h:18420:8: note: previous definition is here
 18420 | struct StateBatch {
       |        ^
In file included from contrib/kafka/filters/network/source/mesh/command_handlers/produce.cc:3:
bazel-out/k8-opt/bin/contrib/kafka/filters/network/source/external/responses.h:19316:7: error: redefinition of 'StateBatchV0Deserializer'
 19316 | class StateBatchV0Deserializer:
       |       ^
bazel-out/k8-opt/bin/contrib/kafka/filters/network/source/external/requests.h:18449:7: note: previous definition is here
 18449 | class StateBatchV0Deserializer:
       |       ^
3 errors generated.

[agrawroh]

LGTM, Thanks!