Resolve dead_code and unused_variables warnings

Summary:
Rust 1.79's dead code scanner is more precise than previous versions. `pub` is no longer sufficient to hide a data structure field from the lint. It actually looks at whether an unused pub field is reachable from outside the crate.

In the following example, the field `field` is considered dead code by Rust 1.79 and not by 1.78.

```lang=rust
mod module {
    pub struct Struct {
        pub field: i32,
    }

    impl Struct {
        pub fn new() -> Self {
            Struct { field: 0 }
        }
    }
}

pub fn repro() {
    let _ = Struct::new();
}
```

Reviewed By: zertosh, JakobDegen

Differential Revision: D59623034

fbshipit-source-id: 6a4e2fb6e5be410d5127b451704df74ecdd42bf0

src/oomd/cfgen/src/types.rs

@@ -43,6 +43,7 @@ pub struct FBTax2Attributes {
 }
 
 pub struct Oomd2Attributes {
+    #[allow(dead_code)]
     pub blacklisted_jobs: Vec<&'static str>,
     pub disable_swap_protection: bool,
     pub kill_target: String,
@@ -57,6 +58,7 @@ pub struct Oomd2Attributes {
     pub oomd_threshold_duration: String,
     pub oomd_restart_threshold: BTreeMap<String, OomdRestartThreshold>,
     pub oomd_reclaim_duation: String,
+    #[allow(dead_code)]
     pub oomd_post_action_delay: String,
     pub swap_protection_detect_threshold: String,
     pub swap_protection_kill_threshold: String,