make Promise use template for exception

in httplug, we have documentation text that formulates that only
specific exceptions may be used for the callback. the change in 1.2.0 to
allow any Throwable was incorrect.

CHANGELOG.md

@@ -1,8 +1,14 @@
 # Change Log
 
-## 1.2.1
+## 1.2.2 - unreleased
 
-### Added - 2023-11-08
+### Fixed
+
+- Changed `Promise` to use a template for the exception class that is allowed.
+
+## 1.2.1 - 2023-11-08
+
+### Fixed
 
 - Fixed PHPDoc for `wait()` and `then()`'s `onRejected` callable
 

src/Promise.php

@@ -14,6 +14,7 @@
  * @author Márk Sági-Kazár <[email protected]>
  *
  * @template-covariant T
+ * @template E of \Throwable
  */
 interface Promise
 {
@@ -38,10 +39,10 @@ interface Promise
      * If you do not care about one of the cases, you can set the corresponding callable to null
      * The callback will be called when the value arrived and never more than once.
      *
-     * @param callable(T): V|null          $onFulfilled called when a response will be available
-     * @param callable(\Throwable): V|null $onRejected  called when an exception occurs
+     * @param callable(T): V|null $onFulfilled called when a response will be available
+     * @param callable(E): V|null $onRejected  called when an exception occurs
      *
-     * @return Promise<V> a new resolved promise with value of the executed callback (onFulfilled / onRejected)
+     * @return Promise<V, E> a new resolved promise with value of the executed callback (onFulfilled / onRejected)
      *
      * @template V
      */
@@ -67,7 +68,7 @@ public function getState();
      *
      * @return ($unwrap is true ? T : null) Resolved value, null if $unwrap is set to false
      *
-     * @throws \Exception the rejection reason if $unwrap is set to true and the request failed
+     * @throws E the rejection reason if $unwrap is set to true and the request failed
      */
     public function wait($unwrap = true);
 }