all: Bump minimum Go version to 1.19

.changes/unreleased/NOTES-20230228-130401.yaml

@@ -0,0 +1,7 @@
+kind: NOTES
+body: 'all: This Go module has been updated to Go 1.19 per the [Go support policy](https://go.dev/doc/devel/release#policy).
+  It is recommended to review the [Go 1.19 release notes](https://go.dev/doc/go1.19)
+  before upgrading. Any consumers building on earlier Go versions may experience errors.'
+time: 2023-02-28T13:04:01.29554-05:00
+custom:
+  Issue: "266"

.github/workflows/ci-protobuf.yml

@@ -37,4 +37,4 @@ jobs:
       - name: git diff
         run: |
           git diff --compact-summary --exit-code || \
-            (echo; echo "Unexpected difference in directories after code generation. Run 'protoc' command and commit."; exit 1)
+            (echo; git diff; echo; echo "Unexpected difference in directories after code generation. Run 'protoc' command and commit."; exit 1)

README.md

@@ -33,7 +33,7 @@ is unsupported by the Terraform Plugin SDK team.
 
 This project follows the [support policy](https://golang.org/doc/devel/release.html#policy) of Go as its support policy. The two latest major releases of Go are supported by the project.
 
-Currently, that means Go **1.18** or later must be used when including this project as a dependency.
+Currently, that means Go **1.19** or later must be used when including this project as a dependency.
 
 ## Getting Started
 

go.mod

@@ -1,6 +1,6 @@
 module github.com/hashicorp/terraform-plugin-go
 
-go 1.18
+go 1.19
 
 require (
 	github.com/google/go-cmp v0.5.9