chore(deps): bump ubuntu from focal-20210609 to focal-20210713 (#64)

Bumps ubuntu from focal-20210609 to focal-20210713.


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Dockerfile

@@ -1,6 +1,6 @@
 #syntax=docker/dockerfile:1.2
 
-FROM ubuntu:focal-20210609 as upstream
+FROM ubuntu:focal-20210713 as upstream
 FROM upstream as base
 
 # Overlay defaults