chore(deps): bump ep_plugin_helpers to ^0.6.0 (#420)

* chore(deps): bump ep_plugin_helpers to ^0.6.0

0.6.x is the current line on npm (latest = 0.6.2) and ^0.5.x doesn't
resolve to it under caret semver for pre-1.0. Without this bump, fresh
installs of this plugin pull ep_plugin_helpers@0.5.3 and miss bug fixes
shipped in 0.6.x — including ether/ep_plugin_helpers#19 which corrected
the misleading "Etherpad < 2.7.4" degradation warning.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* chore(deps): regenerate pnpm-lock.yaml for ep_plugin_helpers bump

Required so the release workflow's `pnpm i --frozen-lockfile` step
doesn't fail with ERR_PNPM_OUTDATED_LOCKFILE after merge.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: JohnMcLear

package.json

@@ -23,7 +23,7 @@
   ],
   "dependencies": {
     "cheerio": "^1.2.0",
-    "ep_plugin_helpers": "^0.5.3",
+    "ep_plugin_helpers": "^0.6.0",
     "formidable": "^3.5.4",
     "underscore": "^1.13.8"
   },