### 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)

for (int i = 0; i < sources.size(); i++) {
		if (sources[i]->try_open_pack(p_path, p_replace_files, p_offset)) {
			return OK;
		}
	}
	return ERR_FILE_UNRECOGNIZED;
}
void PackedData::add_path(const String &p_pkg_path, const String &p_path, uint64_t p_ofs, uint64_t p_size, const uint8_t *p_md5, PackSource *p_src, bool p_replace_files, bool p_encrypted) {
	PathMD5 pmd5(p_path.md5_buffer());
	bool exists = files.has(pmd5);
	PackedFile pf;
	pf.encrypted = p_encrypted;
	pf.pack = p_pkg_path;
	pf.offset = p_ofs;
	pf.size = p_size;
	for (int i = 0; i < 16; i++) {
		pf.md5[i] = p_md5[i];
	}
	pf.src = p_src;
	if (!exists || p_replace_files) {
		files[pmd5] = pf;
	}
	if (!exists) {
		
		String p = p_path.replace_first("res://", "");
		PackedDir *cd = root;
		if (p.contains("/")) { 
			Vector<String> ds = p.get_base_dir().split("/");
			for (int j = 0; j < ds.size(); j++) {