L2SS-497: Add casacore as a requirement, which we'll need in the beam device

tangostationcontrol/requirements.txt

@@ -11,3 +11,4 @@ h5py >= 3.5.0 # BSD
 psutil >= 5.8.0 # BSD
 docker >= 5.0.3 # Apache 2
 python-logstash-async >= 2.3.0 # MIT
+python-casacore >= 3.3.1 # GPL2