Issue: act does not update actions if version is taken from branch

[igagis]

System information

- Operating System:  Linux
- Architecture: x86 (32-bit), arm (32-bit)
- Apple M1: no
- Docker version: 20.10.8
- Docker image used in `act`: `arm32v7/debian:buster`
- `act` version: ?

Expected behaviour

1. refer to a custom action via branch name, e.g. master:

- uses: myci-actions/add-deb-repo@master
# ...

2. run workflow
3. update the action, so that master points to another commit
4. run workflow

Result: on step 4 the updated action is used

Actual behaviour

on step 4 the old action is used. Repeating the workflow run makes it to use the proper updated action.

Workflow and/or repository

Log

⭐  Run ChristopherHX/ghat2/.github/comp1@issue-49
  ☁  git clone 'https://github.com/ChristopherHX/ghat2' # ref=issue-49
  cloning https://github.com/ChristopherHX/ghat2 to C:\Users\Christopher\.cache\act/ChristopherHX-ghat2-.github-comp1@issue-49
Provided ref is not a sha. Checking out branch before pulling changes
Unable to pull refs/heads/issue-49: non-fast-forward update
Cloned https://github.com/ChristopherHX/ghat2 to C:\Users\Christopher\.cache\act/ChristopherHX-ghat2-.github-comp1@issue-49
Checked out issue-49
open C:\Users\Christopher\.cache\act\ChristopherHX-ghat2-.github-comp1@issue-49\.github\comp1\action.yaml: Das System kann den angegebenen Pfad nicht finden.
open C:\Users\Christopher\.cache\act\ChristopherHX-ghat2-.github-comp1@issue-49\.github\comp1\action.yaml: Das System kann den angegebenen Pfad nicht finden.
  ❌  Failure - ChristopherHX/ghat2/.github/comp1@issue-49

info

I faced this issue in context of github actions runner based on act, see corresponding issue there: ChristopherHX/github-act-runner#49

[ChristopherHX]

After looking more in the src of act...
The new branch ref is fetched, but refs/heads/<branchname> still points to the last pulled branch revision.

act/pkg/common/git.go

Line 337 in de44a50

if hash, err = r.ResolveRevision(rev); err != nil {

Then pull failes, which seem to be ok. (or it actually doesn't failed due to force?)
Now this function does a checkout to the previous commit sha which is not uptodate after the branch pull.

act/pkg/common/git.go

Lines 377 to 395 in de44a50

	logger.Debugf("Cloned %s to %s", input.URL, input.Dir)
	if err = w.Checkout(&git.CheckoutOptions{
	Hash: *hash,
	Force: true,
	}); err != nil {
	logger.Errorf("Unable to checkout %s: %v", *hash, err)
	return err
	}
	if err = w.Reset(&git.ResetOptions{
	Mode: git.HardReset,
	Commit: *hash,
	}); err != nil {
	logger.Errorf("Unable to reset to %s: %v", hash.String(), err)
	return err
	}
	logger.Debugf("Checked out %s", input.Ref)

calling the function again corrects this if the branch hasn't changed between the two calls. Better log the commit hash as it is the wrong one in this case.