token.cpp: use snprintf() to fix -Wdeprecated-declarations AppleClang warning (#7744)

```
/Users/runner/work/cppcheck/cppcheck/lib/token.cpp:1611:21: error: 'sprintf' is deprecated: This function is provided for compatibility reasons only.  Due to security concerns inherent in the design of sprintf(3), it is highly recommended that you use snprintf(3) instead. [-Werror,-Wdeprecated-declarations]
 1611 |                     sprintf(str, "\\x%02x", c);
      |                     ^
/Applications/Xcode_16.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.0.sdk/usr/include/_stdio.h:274:1: note: 'sprintf' has been explicitly marked deprecated here
  274 | __deprecated_msg("This function is provided for compatibility reasons only.  Due to security concerns inherent in the design of sprintf(3), it is highly recommended that you use snprintf(3) instead.")
      | ^
/Applications/Xcode_16.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.0.sdk/usr/include/sys/cdefs.h:218:48: note: expanded from macro '__deprecated_msg'
  218 |         #define __deprecated_msg(_msg) __attribute__((__deprecated__(_msg)))
      |                                                       ^
```

Author: firewave

lib/token.cpp

@@ -1607,8 +1607,8 @@ static std::string stringFromTokenRange(const Token* start, const Token* end)
                 else if (c >= ' ' && c <= 126)
                     ret += c;
                 else {
-                    char str[10];
-                    sprintf(str, "\\x%02x", c);
+                    char str[5];
+                    snprintf(str, sizeof(str), "\\x%02x", c);
                     ret += str;
                 }
             }