Add launchable into CI

[ono-max]

@ko1 san allowed me to integrate Launchable into ruby/vscode-rdbg. By introducing Launchable, we can get the following benefits: For more details in Launchable Web Console, please take a look at https://app.launchableinc.com/organizations/demo/workspaces/demo/data/test-sessions.

Test reports in Github comments.

We can check the test results easily.

Rich UI to see stderr and stdout in failed tests

Analysis for Flakey tests

[launchable-app[bot]]

Launchable Report

:white_check_mark: All test sessions passed!

Passed test sessions

:white_check_mark: Test session [#2593876](https://app.launchableinc.com/organizations/ruby/workspaces/vscode-rdbg/data/test-sessions/2593876) passed [](https://app.launchableinc.com/organizations/ruby/workspaces/vscode-rdbg/data/test-sessions/2593876) [](https://app.launchableinc.com/organizations/ruby/workspaces/vscode-rdbg/data/test-sessions/2593876) :white_check_mark: Test session [#2593878](https://app.launchableinc.com/organizations/ruby/workspaces/vscode-rdbg/data/test-sessions/2593878) passed [](https://app.launchableinc.com/organizations/ruby/workspaces/vscode-rdbg/data/test-sessions/2593878) [](https://app.launchableinc.com/organizations/ruby/workspaces/vscode-rdbg/data/test-sessions/2593878) :white_check_mark: Test session [#2593888](https://app.launchableinc.com/organizations/ruby/workspaces/vscode-rdbg/data/test-sessions/2593888) passed [](https://app.launchableinc.com/organizations/ruby/workspaces/vscode-rdbg/data/test-sessions/2593888) [](https://app.launchableinc.com/organizations/ruby/workspaces/vscode-rdbg/data/test-sessions/2593888)

Build: 6e21ad3081ad2dba6fc0b4c12a92265025b9a809