refactor: use slices.Equal to simplify code (#4764)

- **PR Description**

In the Go 1.21 standard library, a new function has been introduced that
enhances code conciseness and readability. It can be find
[here](https://pkg.go.dev/slices@go1.21.1#Equal).

pkg/commands/git_commands/main_branches.go

@@ -1,6 +1,7 @@
 package git_commands
 
 import (
+	"slices"
 	"strings"
 	"sync"
 
@@ -43,7 +44,7 @@ func (self *MainBranches) Get() []string {
 
 	configuredMainBranches := self.c.UserConfig().Git.MainBranches
 
-	if self.existingMainBranches == nil || !utils.EqualSlices(self.previousMainBranches, configuredMainBranches) {
+	if self.existingMainBranches == nil || !slices.Equal(self.previousMainBranches, configuredMainBranches) {
 		self.existingMainBranches = self.determineMainBranches(configuredMainBranches)
 		self.previousMainBranches = configuredMainBranches
 	}

pkg/utils/slice.go

@@ -179,18 +179,3 @@ func Shift[T any](slice []T) (T, []T) {
 	slice = slice[1:]
 	return value, slice
 }
-
-// Compares two slices for equality
-func EqualSlices[T comparable](slice1 []T, slice2 []T) bool {
-	if len(slice1) != len(slice2) {
-		return false
-	}
-
-	for i := range slice1 {
-		if slice1[i] != slice2[i] {
-			return false
-		}
-	}
-
-	return true
-}