linkwarden: use npx for Playwright install command

Replaces 'yarn playwright install' with 'npx playwright install' in both update and install scripts to ensure consistent Playwright installation regardless of local yarn configuration.

ct/linkwarden.sh

@@ -58,7 +58,7 @@ function update_script() {
     fi
     $STD yarn
     $STD npx playwright install-deps
-    $STD yarn playwright install
+    $STD npx playwright install
     mv /opt/.env /opt/linkwarden/.env
     $STD yarn prisma:generate
     $STD yarn web:build

install/linkwarden-install.sh

@@ -49,7 +49,7 @@ if command -v corepack >/dev/null 2>&1; then
 fi
 $STD yarn
 $STD npx playwright install-deps
-$STD yarn playwright install
+$STD npx playwright install
 IP=$(hostname -I | awk '{print $1}')
 cat <<EOF >/opt/linkwarden/.env
 NEXTAUTH_SECRET=${SECRET_KEY}