Use sync gzip, remove bash retry workaround

All zlib calls in the dependency chain now use sync versions,
eliminating the uncaught async errors. No need for process-level
retries.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: rom1504

.github/workflows/ci.yml

@@ -52,9 +52,4 @@ jobs:
       - name: Install Dependencies
         run: npm install
       - name: Start Tests
-        run: |
-          for attempt in 1 2 3; do
-            npm run mocha_test -- -g ${{ matrix.mcVersion }}v && exit 0
-            echo "Attempt $attempt failed, retrying..."
-          done
-          exit 1
+        run: npm run mocha_test -- -g ${{ matrix.mcVersion }}v

src/lib/playerDat.js

@@ -8,9 +8,8 @@ const zlib = require('zlib')
 const { promisify } = require('util')
 const convertInventorySlotId = require('./convertInventorySlotId')
 
-const _gzip = promisify(zlib.gzip)
-async function gzip (data) {
-  try { return await _gzip(data) } catch (err) { throw new Error('gzip failed: ' + err.message) }
+function gzip (data) {
+  return zlib.gzipSync(data)
 }
 
 const nbtParse = promisify(nbt.parse)