Support Taskcluster actions in Github repositories

[ahal]

No description provided.

[firefoxci-taskcluster]

Uh oh! Looks like an error!

SyntaxError at template.tasks[0]: Unexpected end of input

[firefoxci-taskcluster]

Uh oh! Looks like an error!

SyntaxError at template.tasks[0]: Unexpected end of input

[firefoxci-taskcluster]

Uh oh! Looks like an error!

SyntaxError at template.tasks[0]: Unexpected end of input

[ahal]

I'm not really sure how to test this because the action hooks contain a hash of the .taskcluster.yml in their names, so attempting to run an action from this PR results in "No such hook" errors (as expected).

But this shouldn't break anything so I propose we land this and then I'll do a follow-up PR to fix anything I missed.

[lissyx]

I'm not really sure how to test this because the action hooks contain a hash of the .taskcluster.yml in their names, so attempting to run an action from this PR results in "No such hook" errors (as expected).

But this shouldn't break anything so I propose we land this and then I'll do a follow-up PR to fix anything I missed.

Yes, as long as we are not breaking GitHub Actions or treeherder badly :). But maybe fix the lint errors?