Update dependency org.testcontainers:testcontainers to v1.21.4 (jenki…

…nsci#458)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Merge pull request jenkinsci#438 from das7pad/stream-step-log-interface

Implement non-buffered streaming for step logs

Merge pull request jenkinsci#423 from das7pad/reset-position

Avoid including unrelated content in step log after parse errors

Merge pull request jenkinsci#421 from janfaracik/remove-up

Remove 'Up' link

Merge pull request jenkinsci#416 from jglick/OutboundAgent

Replacing `docker-fixtures` with `OutboundAgent`

Merge pull request jenkinsci#401 from jglick/dockerImage

Deprecate `ArtifactManagerTest` functions taking `DockerImage`

Merge pull request jenkinsci#391 from basil/JENKINS-75532

[JENKINS-75532] Fix compatibility layer

Merge pull request jenkinsci#383 from basil/acegi

`FlowExecution#getAuthentication2`

Merge pull request jenkinsci#373 from jglick/StepExecution.acceptAll

`StepExecutionIterator.accept`

Merge pull request jenkinsci#372 from basil/jakarta

Migrate from EE 8 to EE 9