fix format err after code block when codegen

udpate msc

port/linux/package/pikascript/PikaStdDevice.pyi

@@ -84,6 +84,8 @@ class GPIO(BaseDev):
             print("cb1", signal)
         io.setCallBack(cb1, io.SIGNAL_RISING)
         ```
+        The `signal` parameter is the signal type.
+        The callback function will be called when the signal is triggered.
         """
 
     def close(self): ...

src/PikaParser.c

@@ -3219,7 +3219,10 @@ static PIKA_BOOL _strCheckCodeBlockFlag(char* sLine) {
     while (pEnd >= pStart && IS_SPACE_OR_TAB(*pEnd)) {
         pEnd--;
     }
-    if (pEnd - pStart >= 5 && strncmp(pStart, "```", 3) == 0) {
+    if (pEnd - pStart < 2) {
+        return PIKA_FALSE;
+    }
+    if (strncmp(pStart, "```", 3) == 0) {
         bStart = PIKA_TRUE;
     }
     if (pEnd - pStart >= 5 && strncmp(pEnd - 2, "```", 3) == 0) {