Cleanup: remove unused interfaces for helpers

I can only guess here: maybe they were added to more clearly document the public
interface of the classes? If so, I don't think that works. Developers who are
not familiar with the convention will just add a new public method to the class
without updating the interface.

pkg/gui/controllers/helpers/commits_helper.go

@@ -12,10 +12,6 @@ import (
 	"github.com/samber/lo"
 )
 
-type ICommitsHelper interface {
-	UpdateCommitPanelView(message string)
-}
-
 type CommitsHelper struct {
 	c *HelperCommon
 
@@ -26,8 +22,6 @@ type CommitsHelper struct {
 	setCommitDescription          func(string)
 }
 
-var _ ICommitsHelper = &CommitsHelper{}
-
 func NewCommitsHelper(
 	c *HelperCommon,
 	getCommitSummary func() string,