Change force:auth to auth

[emregunel]

Since sfdx v50.0, force:auth commands are moved to their own namespace.
There are some issues to use force:auth, and they are appearently affecting this action.

With current set-up, the action exits with error code:

/home/runner/work/_actions/sfdx-actions/setup-sfdx/v1/index.js:32
    if(error) throw(stderr)
              ^
 ›   Warning: force:auth:sfdxurl:store is not a sfdx command.
Did you mean auth:sfdxurl:store? [y/n]:  ›   Error: Run sfdx help force for a list of available commands.

Auth namespace should be used from now on instead of force:auth.

[daveespo]

The new CLI version just broke our CI/CD. Thanks for the speedy fix!

[fechanique]

merged, thank you!

[daveespo]

@fechanique --- any chance you'd consider tagging the HEAD of master with v1 so we don't have to go through and revise all of our GH Action workflows to pull from HEAD?

If you'd prefer to keep versioning intact, can you tag HEAD with v2 so we can pin to a tag in our workflow?

[fechanique]

@daveespo that's right, I have updated the v1 tag with the latest code! than you!