Introduce tests bcond for easier Python 3.N+1 bootstrap

There is a giant dependency loop between pytest-{timeout,cov}, virtualenv and this.

python-filelock.spec

@@ -5,6 +5,7 @@
 %else
 %bcond_with docs
 %endif
+%bcond_without tests
 
 Name:           python-%{srcname}
 Version:        3.3.1
@@ -19,11 +20,13 @@ BuildArch:      noarch
 
 BuildRequires:  python3-devel
 BuildRequires:  pyproject-rpm-macros
+%if %{with tests}
 # We cannot install extra dependencies because there are some
 # we do not have in Fedora like covdefaults in testing or furo in docs.
 # Test dependencies
 BuildRequires:  python3-pytest
 BuildRequires:  python3-pytest-timeout
+%endif
 %if %{with docs}
 # Doc dependencies
 BuildRequires:  python3-sphinx
@@ -87,7 +90,11 @@ install -p -m0644 -D docs/man/%{srcname}.1 %{buildroot}%{_mandir}/man1/%{srcname
 %endif
 
 %check
+%if %{with tests}
 %pytest
+%else
+%pyproject_check_import
+%endif
 
 %if %{with docs}
 %files doc