Release vroom 1.6.3

[jennybc]

Prepare for release:

• git pull
• Check current CRAN check results
• Polish NEWS
• urlchecker::url_check()
• devtools::build_readme()
• devtools::check(remote = TRUE, manual = TRUE)
• devtools::check_win_devel()
• revdepcheck::cloud_check()
• Update cran-comments.md
• git push

Submit to CRAN:

• usethis::use_version('patch')
• devtools::submit_cran()
• Approve email

Wait for CRAN...

• Accepted 🎉
• usethis::use_github_release()
• usethis::use_dev_version(push = TRUE)

[jennybc]

Re: current CRAN results:

Version: 1.6.1
Check: C++ specification
Result: NOTE
     Specified C++11: please drop specification unless essential
Flavors: [r-devel-linux-x86_64-debian-clang](https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-debian-clang/vroom-00check.html), [r-devel-linux-x86_64-debian-gcc](https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-debian-gcc/vroom-00check.html), [r-devel-linux-x86_64-fedora-clang](https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-fedora-clang/vroom-00check.html), [r-devel-linux-x86_64-fedora-gcc](https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-fedora-gcc/vroom-00check.html), [r-devel-windows-x86_64](https://www.r-project.org/nosvn/R.check/r-devel-windows-x86_64/vroom-00check.html), [r-patched-linux-x86_64](https://www.r-project.org/nosvn/R.check/r-patched-linux-x86_64/vroom-00check.html), [r-release-linux-x86_64](https://www.r-project.org/nosvn/R.check/r-release-linux-x86_64/vroom-00check.html), [r-release-macos-arm64](https://www.r-project.org/nosvn/R.check/r-release-macos-arm64/vroom-00check.html), [r-release-macos-x86_64](https://www.r-project.org/nosvn/R.check/r-release-macos-x86_64/vroom-00check.html), [r-release-windows-x86_64](https://www.r-project.org/nosvn/R.check/r-release-windows-x86_64/vroom-00check.html)

So I removed SystemRequirements: C++11.

[jennybc]

First attempt (what would have been v1.6.2) failed with this new warning from CRAN's incoming Debian checks:

* using log directory ‘/srv/hornik/tmp/CRAN/vroom.Rcheck’
* using R Under development (unstable) (2023-04-27 r84336)
* using platform: x86_64-pc-linux-gnu (64-bit)
* R was compiled by
    Debian clang version 15.0.6
    GNU Fortran (Debian 12.2.0-14) 12.2.0
* running under: Debian GNU/Linux 12 (bookworm)
...
* checking for missing documentation entries ... WARNING
Undocumented code objects:
  ‘.conflicts.OK’
All user-level objects in a package should have documentation entries.
See chapter ‘Writing R documentation files’ in the ‘Writing R
Extensions’ manual.

So I'm trying a simpler approach to .conflicts.OK (b547cd5) and submitting as version 1.6.3.