feat(rulesets): add state migration to clean up removed fields

Follows on from #4697 to cleanup the state automatically.

Signed-off-by: Jacob Bednarz <[email protected]>

go.mod

@@ -79,6 +79,7 @@ require (
 	github.com/hashicorp/terraform-json v0.23.0 // indirect
 	github.com/hashicorp/terraform-registry-address v0.2.3 // indirect
 	github.com/hashicorp/terraform-svchost v0.1.1 // indirect
+	github.com/jinzhu/copier v0.4.0 // indirect
 	github.com/kr/text v0.2.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect

go.sum

@@ -149,6 +149,8 @@ github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 h1:BQSFePA1RWJOl
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99/go.mod h1:1lJo3i6rXxKeerYnT8Nvf0QmHCRC1n8sfWVwXF2Frvo=
 github.com/jhump/protoreflect v1.15.1 h1:HUMERORf3I3ZdX05WaQ6MIpd/NJ434hTp5YiKgfCL6c=
 github.com/jhump/protoreflect v1.15.1/go.mod h1:jD/2GMKKE6OqX8qTjhADU1e6DShO+gavG9e0Q693nKo=
+github.com/jinzhu/copier v0.4.0 h1:w3ciUoD19shMCRargcpm0cm91ytaBhDvuRpz1ODO/U8=
+github.com/jinzhu/copier v0.4.0/go.mod h1:DfbEm0FYsaqBcKcFuvmOZb218JkPGtvSHsKg8S8hyyg=
 github.com/kevinburke/ssh_config v1.2.0 h1:x584FjTGwHzMwvHx18PXxbBVzfnxogHaAReU4gf13a4=
 github.com/kevinburke/ssh_config v1.2.0/go.mod h1:CT57kijsi8u/K/BOFA39wgDQJ9CxiF4nAY/ojJ6r6mM=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=