bump Go requirement to 1.20

Author: FGasper

.github/workflows/all.yml

@@ -22,7 +22,7 @@ jobs:
 
           # This is hard-coded by design in order to catch inadvertent changes
           # to the minimum-required Go version to build migration-verifier.
-          - 1.19
+          - 1.20
           - stable
 
     runs-on: ${{matrix.os.runsOn}}

go.mod

@@ -1,6 +1,6 @@
 module github.com/10gen/migration-verifier
 
-go 1.19
+go 1.20
 
 require (
 	github.com/deckarep/golang-set/v2 v2.3.0