Problem compiling the test_fs_lz4fs_package tests with Closure

Encountered this error when attempting to add a test for #13952. Doesn't look related to the actual PR changes.

building:ERROR: Closure compiler run failed:

building:ERROR: tmpibmsttdm.js:34:6: ERROR - [JSC_VAR_MULTIPLY_DECLARED_ERROR] Variable Module declared more than once. First occurrence: tmpibmsttdm.js
  34|   var Module = typeof Module !== 'undefined' ? Module : {};
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

1 error(s), 0 warning(s)

emcc: error: closure compiler failed (rc: 1): /usr/bin/node --max_old_space_size=8192 /data/git/emscripten/node_modules/.bin/google-closure-compiler --compilation_level ADVANCED_OPTIMIZATIONS --language_in ECMASCRIPT_2020 --language_out NO_TRANSPILE --emit_use_strict=false --externs tmpmvx2ug8d.js --externs tmp79827_80.js --externs tmp6o_jlztc.js --externs tmpxwba9jq2.js --externs tmp382zomzg.js --externs tmpq8he8pup.js --externs tmpwqde740f.js --externs tmpbiwhppv7.js --externs tmp19p_lgrv.js --externs tmpdlqse9gz.js --externs tmpu6i3rdso.js --externs tmp9lct7m3n.js --externs tmpcv9sdu3e.js --externs tmpve097uvf.js --externs tmp27xik64p.js --externs tmpdt592sob.js --externs tmpu6bnzr8g.js --externs tmpc73mcc_z.js --externs tmpqdhr8_7a.js --externs tmpn4nu4ajb.js --externs tmpzznh_835.js --externs tmp1lx7punf.js --externs tmpabel3_xa.js --externs tmpkpjqey69.js --externs tmp5zs9jeim.js --externs tmpr_0ae19p.js --externs tmpw751qa4a.js --externs tmp9vt4ia_j.js --externs tmpxyoav8km.js --externs tmp5e3cru1_.js --externs tmp5yqkdd4t.js --externs tmpy41e2_fh.js --js_output_file tmpgkx6wixi.cc.js --formatting PRETTY_PRINT --js tmpibmsttdm.js
FAIL
[Browser harness server terminated]