CI: set a short timeout

Sometimes minitest starts and then just hangs printing ...nothing?

    Run options: --seed 34017

    # Running:

    Error: The operation was canceled.

Github's default job timeout is a generous 6 hours!
https://docs.github.com/en/actions/learn-github-actions/usage-limits-billing-and-administration#usage-limits
But waiting is not productive and wasteful (and will burn our free minutes).

Setting outer job timeout longer for `bundle install`.
Hoping an inner SIGTERM received from while job is still running may allow
the test to print some traceback.  I have no idea where it's getting stuck.
(macos has no `timeout` command, but most or all stuck runs were linux.)

(I would suspect `exercise_watcher_with_timeout` but also saw same
symptoms on another PR without k0s tests)

.github/workflows/actions.yml

@@ -18,7 +18,9 @@ jobs:
         - os: 'macos-latest'
           command: 'bundle exec rake test'
         - os: ubuntu-latest
-          command: 'test/config/update_certs_k0s.rb'
+          # Sometimes minitest starts and then just hangs printing nothing.
+          # Github by default kills after 6hours(!). Hopefully SIGTERM may let it print some details?
+          command: 'timeout --signal=TERM 3m test/config/update_certs_k0s.rb'
         include:
         # run rubocop against lowest supported ruby
         - os: ubuntu-latest
@@ -35,4 +37,5 @@ jobs:
     - run: gem install rake bundler
     - run: bundle install
     - run: ${{ matrix.os_and_command.command }}
+    timeout-minutes: 10