File python-cluster.spec of Package failed_python-cluster

```
Name:           python-cluster
Version:        1.4.1.post2
Release:        1.1
Summary:        A simple hierarchical clustering library for Python

License:        MIT
URL:            https://pypi.org/project/cluster/
Source0:        https://files.pythonhosted.org/packages/source/c/cluster/cluster-%{version}.tar.gz

BuildRequires:  python3-setuptools
BuildArch:      noarch

%description
A simple hierarchical clustering library for Python.

%prep
%setup -q -n cluster-%{version}

%build
%py3_build

%install
%py3_install

%files
%license LICENSE
%doc README.md
%{python3_sitelib}/cluster/
%{python3_sitelib}/cluster-%{version}-py*.egg-info
```

### Explanation of Changes:
1. **Added `BuildRequires: python3-setuptools`:**
   - This ensures that the `setuptools` package is installed in the build environment before the `%build` phase begins.
   - Without this, the `setup.py` script cannot import `setuptools`, leading to the `ModuleNotFoundError`.

2. **No other changes were made:**
   - The rest of the `.spec` file remains unchanged as there are no other issues indicated in the build log.

### Expected Outcome:
With this modification, the build process should now succeed because the `setuptools` dependency will be satisfied, allowing the `setup.py` script to execute correctly.