made sure that variant missing has a witness

src/lints/enum_variant_missing.ron

@@ -56,4 +56,7 @@ SemverQuery(
     },
     error_message: "A publicly-visible enum has at least one variant that is no longer available under its prior name. It may have been renamed or removed entirely.",
     per_result_error_template: Some("variant {{enum_name}}::{{variant_name}}, previously in file {{span_filename}}:{{span_begin_line}}"),
+    witness: (
+        hint_template: r#"let witness = {{join "::" path}}::{{variant_name}};"#,
+    ),
 )

test_outputs/witnesses/enum_variant_missing.snap

@@ -0,0 +1,14 @@
+---
+source: src/query.rs
+description: "Lint `enum_variant_missing` did not have the expected witness output.\nSee https://github.com/obi1kenobi/cargo-semver-checks/blob/main/CONTRIBUTING.md#testing-witnesses\nfor more information."
+expression: "&actual_witnesses"
+---
+[["./test_crates/enum_struct_variant_field_missing/"]]
+filename = 'src/lib.rs'
+begin_line = 14
+hint = 'let witness = enum_struct_variant_field_missing::IgnoredEnum::StructVariantWillBeMissing;'
+
+[["./test_crates/enum_variant_missing/"]]
+filename = 'src/lib.rs'
+begin_line = 5
+hint = 'let witness = enum_variant_missing::VariantWillBeRemoved::Bar;'