chore: fix some comments (#2603)

Signed-off-by: zhoujiaweii <[email protected]>

Author: zhoujiaweii

integration-tests/public/upgradeable-contracts/set-code-hash-migration/lib.rs

@@ -14,7 +14,7 @@ pub mod incrementer {
     ///
     /// # Note
     ///
-    /// Is is important to realize that after the call to `set_code_hash` the contract's
+    /// It is important to realize that after the call to `set_code_hash` the contract's
     /// storage remains the same.
     ///
     /// If you change the storage layout in your storage struct you may introduce

integration-tests/public/upgradeable-contracts/set-code-hash/lib.rs

@@ -15,7 +15,7 @@ pub mod incrementer {
     ///
     /// # Note
     ///
-    /// Is is important to realize that after the call to `set_code_hash` the contract's
+    /// It is important to realize that after the call to `set_code_hash` the contract's
     /// storage remains the same.
     ///
     /// If you change the storage layout in your storage struct you may introduce