Release shinychat 0.4.0

Prepare for release: - [x] `git pull` - [x] Check [current CRAN check results](https://cran.rstudio.org/web/checks/check_results_shinychat.html) - [x] [Advance deprecations](https://lifecycle.r-lib.org/articles/communicate.html#gradual-deprecation), if needed (only `chat_mod_ui(client=)` from 0.3.0 — too early to advance) - [x] [Polish NEWS](https://style.tidyverse.org/news.html#news-release) - [x] `urlchecker::url_check()` - [x] `devtools::check(remote = TRUE, manual = TRUE)` (0 errors, 0 warnings, 0 notes; 1 local HTML tidy note only) - [ ] `devtools::check_win_devel()` (win-builder.r-project.org is timing out) - [ ] `revdepcheck::cloud_check()` (skipping for now) - [x] Update `cran-comments.md` - [x] `git push` - [ ] Draft blog post - [x] Check that shinychat js assets are up-to-date (`make js-build && make r-update-dist`) Submit to CRAN: - [ ] `usethis::use_version('minor')` - [ ] `devtools::submit_cran()` - [ ] Approve email Wait for CRAN... - [ ] Accepted :tada: - [ ] Finish & publish blog post - [ ] Add link to blog post in pkgdown news menu - [ ] `usethis::use_github_release()` - [ ] `usethis::use_dev_version(push = TRUE)` - [ ] Share on social media - [ ] Slack link to blog post, bluesky, and linkedin in #open-source-comms