🐛 Fix target repository creds. (#173)

This spot missed.  
Related to: konveyor/tackle2-addon#75 - handle
working with multiple repositories concurrently in 0.8.

```
    - '[RULESET] fetching: id=30 (__Target(Test)-ac32d015-93df-11f0-8d81-4661cd220ef3)'
    - '[GIT] Home (directory): /addon/.git/8c35e7c2'
    - '[GIT] Cloning: https://github.com/abrugaro/book-server'
    - '[CMD] /usr/bin/git succeeded.'
```

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Bug Fixes**
* Improved error handling when associating identities with ruleset
repositories so identity lookup failures are reported early and prevent
partial repository setup.

* **Refactor**
* Repository initialization updated to a more flexible options-based
pattern, improving extensibility while preserving existing behavior for
users.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Signed-off-by: Jeff Ortel <[email protected]>

Author: jortel

cmd/rules.go

@@ -220,14 +220,20 @@ func (r *Rules) addRuleSetRepository(ruleset *api.RuleSet) (err error) {
 	if err != nil {
 		return
 	}
-	var ids []api.Ref
+	var options []any
 	if ruleset.Identity != nil {
-		ids = []api.Ref{*ruleset.Identity}
+		var identity *api.Identity
+		identity, err = addon.Identity.Get(ruleset.Identity.ID)
+		if err == nil {
+			options = append(options, identity)
+		} else {
+			return
+		}
 	}
 	rp, err := repository.New(
 		rootDir,
 		ruleset.Repository,
-		ids)
+		options...)
 	if err != nil {
 		return
 	}