Add configurable Timeout

[braedongough]

This is my new favourite github action, thank you for creating this!

Currently, the action defaults to a 60 second timeout, however, I can see the githubApplication.create method has already been written to accept a timeout.

Would you be open to a PR making timeout an optional parameter that can be passed to the action?

[fourass]

Hello,
Anything new regarding this Issue ? We are using this action quite often and it's amazing, but sometimes our jobs exceeds the 1h TTL, and we don't have a way to set a better TTL for the token we retrieve,
Any advice on this ?

[gameofby]

It seems that 1 hour timeout is the default setting from Create an installation access token for an app

Installation tokens expire one hour from the time you create them.

And the current action calls this installation api to get the access token under the hood.

An issue from create-github-app-token also mentioned this.