more correct error code - it's the state that isn't mutated, not the rune

packages/svelte/src/compiler/phases/2-analyze/index.js

@@ -218,7 +218,7 @@ export function analyze_module(ast, options) {
 	for (const [, scope] of scopes) {
 		for (const [name, binding] of scope.declarations) {
 			if (binding.kind === 'state' && !binding.mutated) {
-				warn(warnings, binding.node, [], 'state-rune-not-mutated', name);
+				warn(warnings, binding.node, [], 'state-not-mutated', name);
 			}
 		}
 	}
@@ -377,7 +377,7 @@ export function analyze_component(root, options) {
 		for (const [, scope] of instance.scopes) {
 			for (const [name, binding] of scope.declarations) {
 				if (binding.kind === 'state' && !binding.mutated) {
-					warn(warnings, binding.node, [], 'state-rune-not-mutated', name);
+					warn(warnings, binding.node, [], 'state-not-mutated', name);
 				}
 			}
 		}

packages/svelte/src/compiler/warnings.js

@@ -22,7 +22,7 @@ const runes = {
 		`It looks like you're using the $${name} rune, but there is a local binding called ${name}. ` +
 		`Referencing a local variable with a $ prefix will create a store subscription. Please rename ${name} to avoid the ambiguity.`,
 	/** @param {string} name */
-	'state-rune-not-mutated': (name) =>
+	'state-not-mutated': (name) =>
 		`${name} is declared with $state(...) but is never updated. Did you mean to create a function that changes its value?`,
 	/** @param {string} name */
 	'non-state-reference': (name) =>