This should make the project easier to setup and use and less likely to break
(through expired user tokens).
After this commit:
* Pickup implicit GHA os.environ $GITHUB_ACTOR and $GITHUB_TOKEN by default.
This will provide a good enough token for read-only access to public
repositories.
* Allow override with custom secret GH_USERNAME and/or GH_TOKEN just as
before in those use cases where a token with additional scopes maybe needed
to perform administrative actions.
The values must be defined and non-blank to be considered.
A non-blank expires token will cause failure (as before).
* Continue on a best-effort basis (of not using any token to access public
repositories) instead of failing the workflow immediately.
* Emit a warning to stderr for diagnostic purpose from GHA and local shell
in scenarios where no token is setup.
This means it is still correct to keep the *.yaml config as-is:
env:
GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
GH_USERNAME: ${{ secrets.GH_USERNAME }}
GH_TOKEN: ${{ secrets.GH_TOKEN }}
Because a normal consumer of this project inside a GHA will utilise their
$GITHUB_ACTOR and $GITHUB_TOKEN values instead of acting upon blank values
for $GH_USERNAME and $GH_TOKEN.
