Fix memory allocation for gsFont path strings

[PS2HomeDeveloper]

Summary

gsKit_init_font allocates Path and Path_DAT using strlen(path), but copies the strings with strcpy, which also writes the terminating NUL byte. Both allocations are therefore one byte too small.

Allocate space for the terminator in both font-path buffers.

Testing

• Build gsKit with the PS2 toolchain.
• Initialize a regular font path and verify the stored path is NUL-terminated.
• Initialize BMP_DAT and PNG_DAT font paths and verify the corresponding .dat path is formed correctly.