fix(forge): fix verify-contract etherscan cloudflare bug (#6079)

* fix `forge verify-contract` etherscan cloudflare bug

Etherscan verification for non-mainnet chains requires a question
mark at the end of the verifier url in order to prevent a forward slash
from being added to the url which trips a cloudflare rule on requests
from ec2 boxes.

Verification on both Goerli and Sepolia both fails without this
character present.

Hardhat-verify does not add the extra forward slash to the verifier url
and has no issues verifying contracts on etherscan.

Fixes #4865, #5251, #5741

* run cargo +nightly fmt -- --check

* check if the api url already ends with ?

Also apply the fix to --verifier-url urls

crates/forge/bin/cmd/verify/etherscan/mod.rs

@@ -264,8 +264,12 @@ impl EtherscanVerificationProvider {
     ) -> Result<Client> {
         let etherscan_config = config.get_etherscan_config_with_chain(Some(chain))?;
 
-        let api_url =
-            verifier_url.or_else(|| etherscan_config.as_ref().map(|c| c.api_url.as_str()));
+        let etherscan_api_url = verifier_url
+            .or_else(|| etherscan_config.as_ref().map(|c| c.api_url.as_str()))
+            .map(str::to_owned)
+            .map(|url| if url.ends_with('?') { url } else { url + "?" });
+
+        let api_url = etherscan_api_url.as_deref();
         let base_url = etherscan_config
             .as_ref()
             .and_then(|c| c.browser_url.as_deref())