### 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)

if (!cd->subdirs.has(ds[j])) {
					PackedDir *pd = memnew(PackedDir);
					pd->name = ds[j];
					pd->parent = cd;
					cd->subdirs[pd->name] = pd;
					cd = pd;
				} else {
					cd = cd->subdirs[ds[j]];
				}
			}
		}
		String filename = p_path.get_file();
		
		if (!filename.is_empty()) {
			cd->files.insert(filename);
		}
	}
}
void PackedData::add_pack_source(PackSource *p_source) {
	if (p_source != nullptr) {
		sources.push_back(p_source);
	}
}
PackedData *PackedData::singleton = nullptr;
PackedData::PackedData() {
	singleton = this;
	root = memnew(PackedDir);
	add_pack_source(memnew(PackedSourcePCK));
}
void PackedData::_free_packed_dirs(PackedDir *p_dir) {