fix(events): remove malformed duplicate invoice_expired definition

[ayomidearegbeshola29-dev]

Fix malformed duplicate invoice_expired definition in events.rs

Summary

This PR fixes a pre-existing compile error on main in
contracts/split/src/events.rs. There were two definitions of
invoice_expired:

• The first (5-arg) form was malformed: its env.events().publish(...)
  call was missing the closing ) and the closing } of the function, and the
  second pub fn invoice_expired began inside that unterminated call.
• The second (4-arg) form was a stray duplicate.

The only caller (lib.rs:11004) invokes invoice_expired(&env, invoice_id, deadline, funded, &invoice.creator) — the 5-arg form — so the intended
function is the first one. This PR keeps that form and removes the malformed
tail + the duplicate, yielding a single, correctly-terminated function.

Before

pub fn invoice_expired(env: &Env, invoice_id: u64, deadline: u64, funded: i128, creator: &Address) {
    env.events().publish(
        ( symbol_short!("split"), symbol_short!("expired"), invoice_id ),
        (deadline, funded, creator.clone()),
/// Data: (deadline, funded)
pub fn invoice_expired(env: &Env, invoice_id: u64, deadline: u64, funded: i128) {
    ...

After

pub fn invoice_expired(env: &Env, invoice_id: u64, deadline: u64, funded: i128, creator: &Address) {
    env.events().publish(
        ( symbol_short!("split"), symbol_short!("expired"), invoice_id ),
        (deadline, funded, creator.clone()),
    );
}

Verification

Resolves the unclosed delimiter parse error at events.rs:1821, which was
blocking cargo check for the whole split crate. (Note: additional, unrelated
compile errors remain on main from other unimplemented helpers/variants that
are tracked by their own issues; this PR addresses only the duplicate-function
parse error.)

This is a housekeeping fix for a pre-existing parse error and is not tied to a
specific campaign issue; it is opened to unblock cargo check on main.