### Godot version

4.0.3

### System information

Windows 10

### Issue description

When loading files from a `pck` generated by Godot, file paths must match the exact string path that they were packed in.

Usually when loading files using `FileAccess`, redundant `/`s will be handled correctly. For example, `res://my//path////here` will resolve to `res://my/path/here`. This is not true for `pck`s.

---

Assuming the default `icon.svg` file has been moved into a new directory at `res://assets/`

```gdscript
# This is valid
FileAccess.open("res://assets/icon.svg", FileAccess.READ)
# This is also valid
FileAccess.open("res://assets//////icon.svg", FileAccess.READ)
```

When loading from a `pck`, the path must match exactly.

```gdscript
var packer := PCKPacker.new()
packer.pck_start("res://test.pck")
packer.add_file("res://my//path/icon.svg", "res://assets/icon.svg")
packer.flush()

ProjectSettings.load_resource_pack("res://test.pck")

# This is valid
FileAccess.open("res://my//path/icon.svg", FileAccess.READ)

# This is not valid
FileAccess.open("res://my/path/icon.svg", FileAccess.READ)
# This is also not valid
FileAccess.open("res://my//path/////icon.svg", FileAccess.READ)
```

### Steps to reproduce

Create a `pck` file and start adding files.

Load the `pck` and try to access files with redundant `/`s (or with the correct number of `/`s, if the files were added with redundant `/`s).

### Minimal reproduction project

Available as a repo here: https://github.com/you-win/pck-loading-inconsistency

Available as a zip:
[pck_loading_inconsistency.zip](https://github.com/godotengine/godot/files/11525206/pck_loading_inconsistency.zip)

return eof;
}
uint8_t FileAccessPack::get_8() const {
	ERR_FAIL_COND_V_MSG(f.is_null(), 0, "File must be opened before use.");
	if (pos >= pf.size) {
		eof = true;
		return 0;
	}
	pos++;
	return f->get_8();
}
uint64_t FileAccessPack::get_buffer(uint8_t *p_dst, uint64_t p_length) const {
	ERR_FAIL_COND_V_MSG(f.is_null(), -1, "File must be opened before use.");
	ERR_FAIL_COND_V(!p_dst && p_length > 0, -1);
	if (eof) {
		return 0;
	}
	int64_t to_read = p_length;
	if (to_read + pos > pf.size) {
		eof = true;
		to_read = (int64_t)pf.size - (int64_t)pos;
	}
	pos += p_length;
	if (to_read <= 0) {
		return 0;
	}
	f->get_buffer(p_dst, to_read);
	return to_read;
}
void FileAccessPack::set_big_endian(bool p_big_endian) {