rlang 1.1.6

• Fixes for CRAN checks.

• Progress towards making rlang conformant with the public C API of R.

• env_browse() and env_is_browsed() are now defunct as they require an API
  that is no longer available to packages (#1727).

• The SEXP iterator of the rlang C library (used in r-lib/memtools) is now
  behind a feature flag because it requires private API accessors. Compile
  rlang with -DRLANG_USE_PRIVATE_ACCESSORS to enable it.

• env_unlock() is now defunct because recent versions of R no long
  make it possible to unlock an environment (#1705). Make sure to use an
  up-to-date version of pkgload (>= 1.4.0) following this change.

• is_dictionaryish() now will return TRUE for NULL (@ilovemane, #1712).