Remove reader_parse_test/translate_module fuzz targets (#1212)

This commit removes the two fuzz targets that we imported from cranelift
when cranelift merged in. These have both uncovered a few issues in the
fuzz targets themselves, for example:

* `translate_module` - this doesn't verify the wasm is valid a head of
  time and cranelift is known to panic on translating invalid wasm
  modules. We also already do a lot of fuzzing of translation of wasm
  modules, so this isn't necessarily buying us anything over what we're
  already fuzzing.

* `reader_parse_test` - discovered in #1205 we already found some "bugs"
  in this but it may not necessarily rise to the level of "needs to be
  run on oss-fuzz for us to find more bugs" yet. It looks like this is
  still somewhat internal so we can re-enable when we've got folks to
  fix the fuzz bugs coming in.

Closes #1205

.github/workflows/main.yml

@@ -108,16 +108,6 @@ jobs:
             | shuf \
             | head -n 100 \
             | xargs cargo fuzz run differential --release --debug-assertions
-    - run: |
-        find fuzz/corpus/reader_parse_test -type f \
-            | shuf \
-            | head -n 100 \
-            | xargs cargo fuzz run reader_parse_test --release --debug-assertions
-    - run: |
-        find fuzz/corpus/translate_module -type f \
-            | shuf \
-            | head -n 100 \
-            | xargs cargo fuzz run translate_module --release --debug-assertions
 
   # Install wasm32-unknown-emscripten target, and ensure `crates/wasi-common`
   # compiles to Emscripten.