Fix typeface of validate_* functions (#1179)

components/Starknet/modules/architecture_and_concepts/pages/Smart_Contracts/system-calls-cairo1.adoc

@@ -65,7 +65,7 @@ Gets information about the currently executing block and the transactions in the
 
 This single system call contains all information for a block, transaction, and execution context.
 
-When an account's `+__validate__+`, +`__validate_deploy__`+, or +`__validate_declare__`+ function calls `get_execution_info`, the return values for `block_timestamp` and `block_number` are modified as follows:
+When an account's `+__validate__+`, `+__validate_deploy__+`, or `+__validate_declare__+` function calls `get_execution_info`, the return values for `block_timestamp` and `block_number` are modified as follows:
 
 * `block_timestamp` returns the hour, rounded down to the nearest hour.
 * `block_number` returns the block number, rounded down to the nearest multiple of 100.