fix: Allow specifying arbitrarily named processors in configs

lib/config/flat-config-schema.js

@@ -188,18 +188,6 @@ function assertIsRuleSeverity(ruleId, value) {
     }
 }
 
-/**
- * Validates that a given string is the form pluginName/objectName.
- * @param {string} value The string to check.
- * @returns {void}
- * @throws {TypeError} If the string isn't in the correct format.
- */
-function assertIsPluginMemberName(value) {
-    if (!/[@a-z0-9-_$]+(?:\/(?:[a-z0-9-_$]+))+$/iu.test(value)) {
-        throw new TypeError(`Expected string in the form "pluginName/objectName" but found "${value}".`);
-    }
-}
-
 /**
  * Validates that a value is an object.
  * @param {any} value The value to check.
@@ -323,7 +311,9 @@ const processorSchema = {
     merge: "replace",
     validate(value) {
         if (typeof value === "string") {
-            assertIsPluginMemberName(value);
+            if (value.includes("/") === -1) {
+                throw new TypeError(`Expected string in the form "pluginName/processorName" but found "${value}".`);
+            }
         } else if (value && typeof value === "object") {
             if (typeof value.preprocess !== "function" || typeof value.postprocess !== "function") {
                 throw new TypeError("Object must have a preprocess() and a postprocess() method.");