rust: alloc: update VecExt to take allocation flags

We also rename the methods by removing the `try_` prefix since the names
are available due to our usage of the `no_global_oom_handling` config
when building the `alloc` crate.

Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240328013603.206764-8-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust/kernel/types.rs

@@ -157,11 +157,11 @@ impl ForeignOwnable for () {
 ///     let mut vec =
 ///         ScopeGuard::new_with_data(Vec::new(), |v| pr_info!("vec had {} elements\n", v.len()));
 ///
-///     vec.try_push(10u8)?;
+///     vec.push(10u8, GFP_KERNEL)?;
 ///     if arg {
 ///         return Ok(());
 ///     }
-///     vec.try_push(20u8)?;
+///     vec.push(20u8, GFP_KERNEL)?;
 ///     Ok(())
 /// }
 ///