pin apache-beam for python 3.9

Author: parthea

samples/beam/requirements.txt

@@ -1,4 +1,5 @@
 apache-beam===2.60.0; python_version == '3.8'
-apache-beam==2.71.0; python_version >= '3.9'
+apache-beam===2.69.0; python_version == '3.9'
+apache-beam==2.71.0; python_version >= '3.10'
 google-cloud-bigtable==2.35.0
 google-cloud-core==2.5.0