chore(main): release signet 0.19.0

[release-please[bot]]

:robot: I have created a release beep boop

0.19.0 (2024-02-01)

Features

• Drop support for Ruby 2.6 (#237)

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[release-please[bot]]

:robot: Release is at https://github.com/googleapis/signet/releases/tag/signet/v0.19.0 :sunflower:

[release-trigger[bot]]

Triggered job: cloud-devrel/client-libraries/signet/release (2024-02-13T21:45:48.743Z)

To trigger again, remove the autorelease: triggered label (in a few minutes).

[release-tool-publish-reporter[bot]]

The release build has started, the log can be viewed here. :sunflower:

[release-tool-publish-reporter[bot]]

:egg: You hatched a release! The release build finished successfully! :purple_heart: