[core] remove unneeded vars from shellcheck (#3899)

* remove unneeded wars

* Update alpine-wireguard-install.sh

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Co-authored-by: Tobias <96661824+CrazyWolf13@users.noreply.github.com>

ct/snipeit.sh

@@ -44,7 +44,7 @@ function update_script() {
     cp /opt/snipe-it-backup/.env /opt/snipe-it/.env
     cp -r /opt/snipe-it-backup/public/uploads/ /opt/snipe-it/public/uploads/
     cp -r /opt/snipe-it-backup/storage/private_uploads /opt/snipe-it/storage/private_uploads
-    cd /opt/snipe-it/ || exit
+    cd /opt/snipe-it/
     export COMPOSER_ALLOW_SUPERUSER=1
     $STD composer install --no-dev --optimize-autoloader --no-interaction
     $STD composer dump-autoload