fix: save vocs cache on failure

Amp-Thread-ID: https://ampcode.com/threads/T-019c0ce1-470a-76b4-bbba-2ac0da737f95
Co-authored-by: Amp <amp@ampcode.com>

Author: jxom

.github/workflows/deploy-docs.yml

@@ -24,6 +24,7 @@ jobs:
         with:
           path: site/.cache
           key: vocs
+          save-always: true
 
       - name: Build package
         run: pnpm build