Upgrade to 3.34 version of Remoting.

[jeffret-b]

See JENKINS-53461. This enables a new connection mode for inbound TCP agents whereby they can skip the initial HTTP connection step by providing sufficient information to connect directly. This is documented, along with a few other existing behaviors, at Launching inbound TCP agents. The PR for this change is located at jenkinsci/remoting#338.

This Remoting release also contains a few other minor cleanup changes, which didn't need a JIRA filed.

See the Remoting changelog

Proposed changelog entries

• Update Remoting from 3.33 to 3.34. (issue 53461, full changelog)

Submitter checklist

• JIRA issue is well described
• Changelog entry appropriate for the audience affected by the change (users or developer, depending on the change). Examples
• Appropriate autotests or explanation to why this change has no tests
• For dependency updates: links to external changelogs and, if possible, full diffs

Desired reviewers

@jvz @oleg-nenashev @alxsap

[oleg-nenashev]

Will merge it later today if no negative feedback

[bbara]

FYI: There exists a problem with tunneling and this version (https://issues.jenkins-ci.org/browse/JENKINS-59094 / jenkinsci/remoting#345).