chore(p2p_service): remove unnecessary cast to usize (#2123)

## Linked Issues/PRs
<!-- List of related issues/PRs -->
- #2112

## Description
<!-- List of detailed changes -->
- Addressing
#2112 (comment)

A follow up PR will be made to address #2121

## Checklist
- [x] Breaking changes are clearly marked as such in the PR description
and changelog
- [x] New behavior is reflected in tests
- [x] [The specification](https://github.com/FuelLabs/fuel-specs/)
matches the implemented behavior (link update PR if changes are needed)

### Before requesting review
- [x] I have reviewed the code myself
- [x] I have created follow-up issues caused by this PR and linked them
here

### After merging, notify other teams

[Add or remove entries as needed]

- [ ] [Rust SDK](https://github.com/FuelLabs/fuels-rs/)
- [ ] [Sway compiler](https://github.com/FuelLabs/sway/)
- [ ] [Platform
documentation](https://github.com/FuelLabs/devrel-requests/issues/new?assignees=&labels=new+request&projects=&template=NEW-REQUEST.yml&title=%5BRequest%5D%3A+)
(for out-of-organization contributors, the person merging the PR will do
this)
- [ ] Someone else?

bin/fuel-core/src/cli/run/p2p.rs

@@ -64,7 +64,7 @@ pub struct P2PArgs {
 
     /// Max number of blocks/headers in a single headers request response
     #[clap(long = "max-headers-per-request", default_value = "100", env)]
-    pub max_headers_per_request: u32,
+    pub max_headers_per_request: usize,
 
     /// Addresses of the bootstrap nodes
     /// They should contain PeerId within their `Multiaddr`

crates/services/p2p/src/config.rs

@@ -47,7 +47,7 @@ const REQ_RES_TIMEOUT: Duration = Duration::from_secs(20);
 pub const MAX_RESPONSE_SIZE: usize = 18 * 1024 * 1024;
 
 /// Maximum number of blocks per request.
-pub const MAX_HEADERS_PER_REQUEST: u32 = 100;
+pub const MAX_HEADERS_PER_REQUEST: usize = 100;
 
 #[derive(Clone, Debug)]
 pub struct Config<State = Initialized> {
@@ -71,7 +71,7 @@ pub struct Config<State = Initialized> {
 
     /// Max Size of a Block in bytes
     pub max_block_size: usize,
-    pub max_headers_per_request: u32,
+    pub max_headers_per_request: usize,
 
     // `DiscoveryBehaviour` related fields
     pub bootstrap_nodes: Vec<Multiaddr>,

crates/services/p2p/src/service.rs

@@ -327,7 +327,7 @@ pub struct Task<P, V, B> {
     request_sender: mpsc::Sender<TaskRequest>,
     database_processor: HeavyTaskProcessor,
     broadcast: B,
-    max_headers_per_request: u32,
+    max_headers_per_request: usize,
     // milliseconds wait time between peer heartbeat reputation checks
     heartbeat_check_interval: Duration,
     heartbeat_max_avg_interval: Duration,
@@ -435,12 +435,10 @@ where
         let instant = Instant::now();
         let timeout = self.response_timeout;
         let response_channel = self.request_sender.clone();
+        let max_len = self.max_headers_per_request;
+
         match request_message {
             RequestMessage::Transactions(range) => {
-                let max_len = self
-                    .max_headers_per_request
-                    .try_into()
-                    .expect("u32 should always fit into usize");
                 if range.len() > max_len {
                     tracing::error!(
                         requested_length = range.len(),
@@ -492,10 +490,6 @@ where
                 }
             }
             RequestMessage::SealedHeaders(range) => {
-                let max_len = self
-                    .max_headers_per_request
-                    .try_into()
-                    .expect("u32 should always fit into usize");
                 if range.len() > max_len {
                     tracing::error!(
                         requested_length = range.len(),