PKGBUILD: preserve current branch

scripts/package_managers/pacman/PKGBUILD

@@ -41,9 +41,7 @@ pkgver() {
 prepare() {
     cd "${pkgname}" || exit 1
     git fetch --prune
-    git checkout main
-    git pull --autostash
-    git checkout "${AL_GIT_REVISION:-origin/main}"
+    git checkout HEAD
 }
 
 build() {