Remove @brief annotations from Rust API docs (#20769)

programs/bpf/rust/realloc/src/instructions.rs

@@ -1,4 +1,4 @@
-//! @brief Example Rust-based BPF realloc test program
+//! Example Rust-based BPF realloc test program
 
 use solana_program::{
     instruction::{AccountMeta, Instruction},

programs/bpf/rust/realloc/src/lib.rs

@@ -1,4 +1,4 @@
-//! @brief Example Rust-based BPF realloc test program
+//! Example Rust-based BPF realloc test program
 
 pub mod instructions;
 pub mod processor;

programs/bpf/rust/realloc/src/processor.rs

@@ -1,4 +1,4 @@
-//! @brief Example Rust-based BPF realloc test program
+//! Example Rust-based BPF realloc test program
 
 #![cfg(feature = "program")]