chore(deps): bump bitnami/kubectl in /test/container (argoproj#18863)

Bumps bitnami/kubectl from `e704ebf` to `3f6d478`.

---
updated-dependencies:
- dependency-name: bitnami/kubectl
  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>

test/container/Dockerfile

@@ -12,7 +12,7 @@ FROM docker.io/library/golang:1.22.4@sha256:a66eda637829ce891e9cf61ff1ee0edf544e
 
 FROM docker.io/library/registry:2.8@sha256:79b29591e1601a73f03fcd413e655b72b9abfae5a23f1ad2e883d4942fbb4351 as registry
 
-FROM docker.io/bitnami/kubectl:1.30@sha256:e704ebf9f6974d506d2dbff33dea28b6e996887e60c4ab298c78e10a3d81e249 as kubectl
+FROM docker.io/bitnami/kubectl:1.30@sha256:3f6d4783cf84b56cb5aa33d0b404b5270aafaa6dcd5afe844b3cd55558383fa2 as kubectl
 
 FROM docker.io/library/ubuntu:24.04@sha256:3f85b7caad41a95462cf5b787d8a04604c8262cdcdf9a472b8c52ef83375fe15