Turns out we have a `@NonNull Run` context for all of the `createClient` overloads. This allows methods to be simplified by dropping the `Job` / `Item` parameter; and allows us to drop the `CredentialsProvider.lookupCredentials` code branch, so that `CredentialsProvider.findCredentialById` can be called whenever there are credentials.
Turns out we have a `@NonNull Run` context for all of the `createClient` overloads.
This allows methods to be simplified by dropping the `Job` / `Item` parameter;
and allows us to drop the `CredentialsProvider.lookupCredentials` code branch,
so that `CredentialsProvider.findCredentialById` can be called whenever there are credentials.

jenkinsci/git-plugin,MarkEWaite/git-plugin,MarkEWaite/git-plugin,martinda/git-plugin,jenkinsci/git-plugin,jenkinsci/git-plugin,MarkEWaite/git-plugin,jenkinsci/git-plugin,martinda/git-plugin,martinda/git-plugin,MarkEWaite/git-plugin