Fix error message when 'yarn check -s' fails in the commit check script

Problem/Motivation

Followup from #3262573-11: Update our yarn dev dependencies to the extent allowed by current constraints.

Currently, the commit check script has some very generic error messaging when yarn check -s exits with an error status:

# Ensure JavaScript development dependencies are installed.                     
yarn check -s 2>/dev/null
if [ "$?" -ne "0" ]; then
  printf "Drupal's JavaScript development dependencies are not installed. Run 'yarn install' inside the core directory.\n"
  DEPENDENCIES_NEED_INSTALLING=1;
fi

There are other reasons that yarn check -s can fail besides the dependencies not being installed. In particular, upstream issues or irresolvable conflicts can also cause the problem, e.g.:

[ayrton:core | Fri 17:31:33] $ yarn check -s
warning ../../../package.json: No license field
error "terser#acorn@^8.5.0" doesn't satisfy found match of "acorn@7.4.1"
warning "eslint#@babel/code-frame#@babel/highlight@^7.10.4" could be deduped from "7.16.10" to "@babel/highlight@7.16.10"
error Found 1 errors.

Proposed resolution

Update the error message text to include other possible causes and solutions.

Remaining tasks

TBD

User interface changes

A change to the CLI and testbot output when yarn fails (not UI per se).

API changes

N/A

Data model changes

N/A

Release notes snippet

N/A