Hardcode STRK balances variable selector (#3332)

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Closes #

## Introduced changes

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-

## Checklist

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- [ ] Linked relevant issue
- [ ] Updated relevant documentation
- [ ] Added relevant tests
- [ ] Performed self-review of the code
- [ ] Added changes to `CHANGELOG.md`

Author: franciszekjob

snforge_std/Scarb.toml

@@ -10,4 +10,3 @@ re-export-cairo-plugins = ["snforge_scarb_plugin"]
 
 [dependencies]
 snforge_scarb_plugin = { path = "../crates/snforge-scarb-plugin" }
-starknet = "*"

snforge_std/src/cheatcodes/erc20.cairo

@@ -3,6 +3,8 @@ use snforge_std::cheatcodes::storage::{map_entry_address, store};
 
 const STRK_CONTRACT_ADDRESS: felt252 =
     0x04718f5a0fc34cc1af16a1cdee98ffb20c31f5cd61d6ab07201858f4287c938d;
+const STRK_BALANCES_VARIABLE_SELECTOR: felt252 =
+    0x3a4e8ec16e258a799fe707996fd5d21d42b29adc1499a370edf7f809d8c458a; // selector!("ERC20_balances");
 
 #[derive(Drop, Serde, Copy, Debug)]
 pub struct CustomToken {
@@ -27,7 +29,7 @@ pub impl TokenImpl of TokenTrait {
 
     fn balances_variable_selector(self: Token) -> felt252 {
         match self {
-            Token::STRK => selector!("ERC20_balances"),
+            Token::STRK => STRK_BALANCES_VARIABLE_SELECTOR,
             Token::Custom(CustomToken {
                 balances_variable_selector, ..,
             }) => balances_variable_selector,