Change default value for codingAgent.codeLens setting

[joshspicer]

while #7962 is under discussion

[joshspicer]

@copilot Fix this test

1 failing

1. IssueTodoProvider
   should provide code lenses for TODO comments:

   AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:

0 !== 1

  + expected - actual

  -0
  +1

This means enabling githubPullRequests.codingAgent.codeLens for the test. Add another small test that confirms that githubPullRequests.codingAgent.codeLens === false does indeed disable the code lens.

[Copilot]

@joshspicer I've opened a new pull request, #7982, to work on those changes. Once the pull request is ready, I'll request review from you.

[joshspicer]

#7981 should be enough?