Style: Relocate godot_gdb_pretty_print.py

[Repiteo]

As godot_gdb_pretty_print.py isn't a file that's meant to be run directly, this PR moves the file from misc/scripts to misc/utility. While doing so, a few minor adjustments were made, namely:

• Removing shebang and executable perms, GDB already handles the file directly.
• Top-level comment replaced with docstring, reformatted to better suit the new context.
• Ignore warnings from import gdb, as this can't technically be resolved (though typeshed properly recognizes it).

[akien-mga]

Thanks!