fix!: no-unused-vars varsIgnorePattern behavior with catch arguments

docs/src/use/migrate-to-9.0.0.md

@@ -28,6 +28,7 @@ The lists below are ordered roughly by the number of users each change is expect
 * [Case-sensitive flags in `no-invalid-regexp`](#no-invalid-regexp)
 * [Stricter `/* exported */` parsing](#exported-parsing)
 * [`"eslint:recommended"` and `"eslint:all"` strings no longer accepted in flat config](#string-config)
+* [Behavior of `varsIgnorePattern` option of `no-unused-vars` rule with catch arguments](#vars-ignore-pattern)
 
 ### Breaking changes for plugin developers
 
@@ -236,6 +237,25 @@ export default [
 
 **Related issue(s):** [#17488](https://github.com/eslint/eslint/issues/17488)
 
+## <a name="vars-ignore-pattern"></a> Behavior of `varsIgnorePattern` option of `no-unused-vars` rule with catch arguments
+
+In previous versions of ESLint, `varsIgnorePattern` option of `no-unused-vars`, that is used to restrict some specified variable to be reported, used to ignore all variables that machtes the specified pattern except `function` arguments because there is a seperate option to ignore them called `argsIgnorePattern` and same was expected for `caughtErrorsIgnorePattern` option but `varsIgnorePattern` was also ignoring `catch` block arguments.
+
+This behavior has been fixed in ESLint v9.0.0, that means `varsIgnorePattern` option don't get applied to both `function` and `catch` block arguments.
+
+```js
+/*eslint no-unused-vars: ["error", { "caughtErrors": "all", "varsIgnorePattern": "^err" }]*/
+
+try {
+    //...
+} catch (err) { // 'err' will be reported.
+    console.error("errors");
+}
+
+```
+
+**Related issue(s):** [#17540](https://github.com/eslint/eslint/issues/17540)
+
 ## <a name="removed-context-methods"></a> Removed multiple `context` methods
 
 ESLint v9.0.0 removes multiple deprecated methods from the `context` object and moves them onto the `SourceCode` object: