applying rustfix for 2024 edition migration

Summary:
First batch of auto fixes that migrate the codebase to edition 2024

Applied rustfix multiple times (new suggestions would appear after applying lints) to the following directories:
```
$rustfix -n --clippy --edition -T //common/rust/...
$rustfix -n --clippy --edition -T //thrift/...
$rustfix -n --clippy --edition -T //cli/...
```

Reviewed By: dtolnay

Differential Revision: D73291267

fbshipit-source-id: 76fe7e442ca3a828b90f2ea5ff419f8067020655

Author: cjlongoria

common/rust/shed/hostcaps/src/lib.rs

@@ -46,27 +46,27 @@ pub fn is_lab() -> bool {
     false
 }
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn fb_get_env() -> u8 {
     get_env() as u8
 }
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn fb_is_prod() -> bool {
     *IN_PROD
 }
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn fb_is_corp() -> bool {
     *IN_CORP
 }
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn fb_is_lab() -> bool {
     *IN_LAB
 }
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn fb_has_servicerouter() -> bool {
     *IN_PROD
 }