Disable share generics to reduce the binary size more (#64335)

After the new macOS nightly with
https://github.com/zed-industries/zed/pull/64260 arrived, I've noticed
that the binary had actually bloated back — run some bisecting and build
comparison, and seems that the shared generics are the culprit.

Platform / executable | Sharing enabled | Sharing disabled/default |
Reduction |
|---|---:|---:|---:|
| macOS ARM64 editor | 304,794,488 bytes | 266,242,792 bytes |
**38,551,696 bytes / 12.65%** |
| Linux x86_64 editor | 334,001,336 bytes | 325,916,104 bytes |
**8,085,232 bytes / 2.42%** |
| Linux x86_64 remote server | 123,618,032 bytes | 106,211,592 bytes |
**17,406,440 bytes / 14.08%**

Each pair uses the same checkout and Rust **1.98.1**, was built with the
bundling script:
- macOS: `e0590874fd`, measured after `strip -x`.
- Linux: `b664a4004269`, measured after `llvm-objcopy --strip-debug
--discard-all`.

The Linux section changes when disabling sharing are:

| Component | Editor | Remote server |
|---|---:|---:|
| Retained `.symtab` + `.strtab` | **−47,560,049 bytes** | **−17,733,989
bytes** |
| Allocated file-backed sections | +39,475,120 bytes | +327,448 bytes |
| Headers, padding, and other bytes | −303 bytes | +101 bytes |
| **Total** | **−8,085,232 bytes** | **−17,406,440 bytes** |


Release Notes:

- N/A

.cargo/bundle-config.toml

@@ -1,9 +1,3 @@
-[env]
-RUSTC_BOOTSTRAP = "1"
-
-[target.'cfg(all())']
-rustflags = ["-Z", "share-generics=y"]
-
 [target.'cfg(target_os = "linux")']
 rustflags = ["-C", "link-args=-Wl,--disable-new-dtags,-rpath,$ORIGIN/../lib"]