Remove dependency on clearpath_generator_common; doing so creates a c…

…ircular dependency. Instead use the system level envar

clearpath_config/manipulators/types/arms.py

@@ -25,6 +25,7 @@
 # CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
+import os
 from typing import List
 
 from clearpath_config.common.types.accessory import Accessory
@@ -33,7 +34,9 @@
 from clearpath_config.common.types.port import Port
 from clearpath_config.manipulators.types.grippers import Gripper
 from clearpath_config.manipulators.types.manipulator import BaseManipulator
-from clearpath_generator_common.ros import ROS_DISTRO
+
+
+ROS_DISTRO = os.environ.get('ROS_DISTRO', 'jazzy')
 
 
 class BaseArm(BaseManipulator):