fix: use correct clarity version for requirements

We can retrieve the clarity version while we retrieve the contract,
since it is now returned from the API. If the version is not specified,
then we can compute the default clarity version for the current epoch
using the block height of the deploy transaction.

Also fill in the exact block number for testnet 2.1 activation.

components/clarinet-deployments/src/requirements.rs

@@ -75,22 +75,17 @@ pub async fn retrieve_contract(
     );
 
     let contract = fetch_contract(request_url).await?;
-
-    let clarity_version = {
-        // `version` defaults to 1 because before 2.1, no version is specified
-        // since Clarity 1 was the only version available.
-        let version = contract.clarity_version.unwrap_or(1);
-        if version.eq(&1) {
-            ClarityVersion::Clarity1
-        } else if version.eq(&2) {
-            ClarityVersion::Clarity2
-        } else {
+    let epoch = epoch_for_height(is_mainnet, contract.publish_height);
+    let clarity_version = match contract.clarity_version {
+        Some(1) => ClarityVersion::Clarity1,
+        Some(2) => ClarityVersion::Clarity2,
+        Some(_) => {
             return Err(format!(
                 "unable to parse clarity_version (can either be '1' or '2'",
-            ));
+            ))
         }
+        None => ClarityVersion::default_for_epoch(epoch),
     };
-    let epoch = epoch_for_height(is_mainnet, contract.publish_height);
 
     match file_accessor {
         None => {
@@ -132,8 +127,7 @@ pub const MAINNET_21_START_HEIGHT: u32 = 99_564;
 pub const TESTNET_20_START_HEIGHT: u32 = 1;
 
 pub const TESTNET_2_05_START_HEIGHT: u32 = 20_216;
-// TODO: This is estimated. Replace with exact height once 2.1 is activated.
-pub const TESTNET_21_START_HEIGHT: u32 = 99_253;
+pub const TESTNET_21_START_HEIGHT: u32 = 99_120;
 
 fn epoch_for_height(is_mainnet: bool, height: u32) -> StacksEpochId {
     if is_mainnet {