[file_packager] Remove unused `errback` fetchRemovePackage. NFC#24904

sbc100 merged 1 commit intoemscripten-core:mainemscripten-core/emscripten:mainfrom

sbc100:file_packager_fix_fetchRemotePackagesbc100/emscripten:file_packager_fix_fetchRemotePackageCopy head branch name to clipboard