[Backport release-23.11] cargo-generate: 0.19.0 -> 0.20.0

[github-actions]

Bot-based backport to release-23.11, triggered by a label in #299485.

• Before merging, ensure that this backport is acceptable for the release.
  • Even as a non-commiter, if you find that it is not acceptable, leave a comment.

[NickCao]

       > error: package `clap_builder v4.5.2` cannot be built because it requires rustc 1.74 or newer, while the currently active rustc version is 1.73.0
       > Either upgrade to rustc 1.74 or newer, or use
       > cargo update -p clap_builder@4.5.2 --precise ver
       > where `ver` is the latest version of `clap_builder` supporting rustc 1.73.0

[matthiasbeyer]

Applied this patch to #298312

Closing this in favor of the above PR.