chore(deps): update dependency apache-beam to v2.26.0 (#185)

Author: renovate-bot

packages/google-cloud-bigtable/samples/beam/requirements.txt

@@ -1,3 +1,3 @@
-apache-beam==2.25.0
+apache-beam==2.26.0
 google-cloud-bigtable==1.6.0
 google-cloud-core==1.4.3