Runtime Version Scanner: Load official EOL versions from an API

[toph-allen]

Currently EOL versions for the Runtime Version Scanner are hard-coded and will need to be updated when new R and Python versions are updated.

connect-extensions/extensions/runtime-version-scanner/app.R

Lines 13 to 17 in de871d8

	# https://devguide.python.org/versions/
	PY_OLDEST_SUPPORTED <- "3.9.0"
	# https://www.tidyverse.org/blog/2019/04/r-version-support/, https://www.r-project.org/
	R_OLDEST_SUPPORTED <- "4.1.0"

It would be better to load these from an API, but no official API exists for either R or Python.

[toph-allen]

For R, we can use:

$ curl -s https://packagemanager.posit.co/__api__/status | jq .r_versions
[
  "4.5",
  "4.4",
  "4.3",
  "4.2",
  "4.1",
  "3.6"
]

We'll just have to manually remove R 3.6.