Re-enable 3 tests disabled for LSP update

[heejaechang]

tagging @karthiknadig

while updating LSP version to the latest in this PR, 2 notebook tests are keep failing due to jupyter extension not installed. specifically, due to this check

await verifyExtensionIsAvailable(JUPYTER_EXTENSION_ID);

in these tests in 'nbextensionCodeLensProvider.insiders.test.ts'

'Provide code lens for Python notebook loading and launching tensorboard nbextension'
'Provide code lens for Python notebook importing tensorboard'

I tried to force the tests to install jupyter extension using INSTALL_JUPYTER_EXTENSION in yml, but even if log says jupyter extension is installed, the test still can't find the extension installed. and fail.

I checked why other PR didn't have this issue and it looks like other PR ran with stable vscode and these tests only run with insider so, test just didn't run for other PRs.

the latest LSP update required 1.67 version of vscode which required insider so, the PR made these tests to run with insiders and that's why those tests ran for the PR.

• I talked Kartik and he asked me to disable the tests for now, and open tracking issue.

[heejaechang]

disabled another test for python 2.7

'Definitions' test in languageServer.insiders.test.ts

I couldn't figure out why this only fails in version 2.7.