Log Message:
(lang/R-cpp11) Updated 0.4.2 to 0.4.3

# cpp11 0.4.3

* Modernized the GitHub Actions workflows and updated some internal tests to
  better align with changes in those workflows and the latest version of R
  (#279)

* `cpp_source()` errors on non-existent file (#261).

* `cpp_register()` is quiet by default when R is non interactive (#289).

* updated test to adapt to changes in R 4.2.1 (#290).