Combine deps install step

[MichaelChirico]

Based on latest failure. R_LIBS_USER part apparently failed, not sure why, here's the .libPaths() that got picked up:

.libPaths()=='/tmp/Rtmp7Zozpg/RLIBS_610b4d40b38b','/opt/R/4.4.1/lib/R/library'

i.e. a session temp directory and the R system install library. I also see this earlier in the log:

  env:
    R_LIBS_USER: /home/runner/work/_temp/Library
    R_REMOTES_NO_ERRORS_FROM_WARNINGS: true
    GITHUB_PAT: ***
    LC_ALL: lv_LV.utf8
    LANGUAGE: lv_LV
    TZ: UTC
    _R_CHECK_SYSTEM_CLOCK_: FALSE
    NOT_CRAN: true
    _R_CHECK_FORCE_SUGGESTS_: false
    _R_CHECK_CRAN_INCOMING_REMOTE_: false
    _R_CHECK_TESTS_NLINES_: 0

Suggesting maybe the r-lib actions are overriding what I tried.

For now, I'll try just combining the deps install step with the check step to avoid the issue altogether.

Lastly, I don't see the cat() output despite I think I should, probably it's not being sent to the right output buffer, hopefully message() works.