v0.19.0

What's Changed

• Add patch_metadata method to kv api by @hortoncd in #277
• defaults: add support for a token file environment variable by @matiasbertani in #291
• Set minimum ruby version to 3.1 by @nevans in #352
• Use upstream net-http-persistent, connection_pool (un-vendored) by @nevans in #345
• Replace deprecated JSON.fast_generate by @nevans in #349
• http client's shutdown should be lock-protected by @fxposter in #329

Full Changelog: v0.18.2...v0.19.0