chore: Update to Go v1.21

- go mod tidy (all modules)
- go work sync
- Fixed plugin generation for Go 1.21
- Updated linting for Go 1.21
- Fixed minecraft example for Helm v3 pull download path
- Update dev docs to mention Go 1.21
- Regenerate plugins with Go 1.21

Makefile-plugins.mk

@@ -96,7 +96,7 @@ generate-kustomize-builtin-plugins: $(builtplugins)
 		echo "generating $${plugin} ..."; \
 		set -e; \
 		cd $${plugin}; \
-		go generate pluginator .; \
+		go generate .; \
 	done
 
 # Check for diff by comparing current revision of generated plugins on HEAD and newly generated plugins on local branch,