fix(ci): Fix CI for Onivim 2 - revert fetch dependencies (#997)

Unfortunately, I'm still seeing issues with the set of dependencies for the `fetch-lwt` library, when building Onivim 2 - we get this error:

I've been trying to avoid reverting this, and maintaining a separate 'oni2' branch w/o it - but it's a lot of extra overhead for me (we can't actually use `fetch` in Onivim 2, either - lack of Windows support & it isn't integrated with libuv).

When building from Onivim 2, I get these errors:
```
Bryans-Mac-mini:oni2 bryphe$ esy run -f
info building @reason-native-web/piaf@1.3.0@d41d8cd9
error: build failed with exit code: 1
  build log:
    # esy-build-package: building: @reason-native-web/piaf@1.3.0
    # esy-build-package: pwd: /Users/bryphe/.esy/source/i/reason_native_web__s__piaf__1.3.0__aac2317a
    # esy-build-package: running: 'dune' 'build' '--only-packages=piaf' '--profile=release' '-j' '4' '--root=./piaf'
    Entering directory '/Users/bryphe/.esy/source/i/reason_native_web__s__piaf__1.3.0__aac2317a/piaf'
    File "lib/http_intf.ml", line 1:
    Error: The files lib/.piaf.objs/byte/piaf__Scheme.cmi
           and /Users/bryphe/.esy/3__________________________________________________________________/i/reason_native_web__s__h2_lwt_unix-0.6.1000-eb9002c6/lib/h2-lwt-unix/h2_lwt_unix.cmi
           make inconsistent assumptions over interface Gluten_lwt_unix__Ssl_io
    error: command failed: 'dune' 'build' '--only-packages=piaf' '--profile=release' '-j' '4' '--root=./piaf' (exited with 1)
    esy-build-package: exiting with errors above...
    
  building @reason-native-web/piaf@1.3.0
esy: exiting due to errors above
```

I'd definitely like to have the `fetch` API - some details here: #996 , and really appreciate all the pioneering work you've done @lessp ! If you have any other ideas, @lessp - let me know 👍