Fuzzer: Fix determinism fuzzing (#4767)
Fuzzer: Fix determinism fuzzing (#4767)

#4758 regressed the determinism fuzzer. First, FEATURE_OPTS is not a
list but a string. Second, as a hack another location would add --strip-dwarf
to that list, but that only works in wasm-opt. To fix that, remove the hack
and instead just ignore DWARF-containing files.
WebAssembly/binaryen,WebAssembly/binaryen,WebAssembly/binaryen,WebAssembly/binaryen,WebAssembly/binaryen