Fix attach file button width on iOS Safari (#5167)

* Fix attach file button width on iOS Safari

* Update PR number

CHANGELOG.md

@@ -62,6 +62,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
    -  Added animation to focus indicator and pixel-perfected, in PR [#5143](https://github.com/microsoft/BotFramework-WebChat/pull/5143)
    -  Integrated focus management for send box, in PR [#5150](https://github.com/microsoft/BotFramework-WebChat/pull/5150), by [@OEvgeny](https://github.com/OEvgeny)
    -  Added keyboard navigation support into suggested actions, in PR [#5154](https://github.com/microsoft/BotFramework-WebChat/pull/5154), by [@OEvgeny](https://github.com/OEvgeny)
+   -  Fixes [#5166](https://github.com/microsoft/BotFramework-WebChat/issues/5166). Fixed "attach file" button in iOS Safari should looks the same as on other platforms, in PR [#5167](https://github.com/microsoft/BotFramework-WebChat/pull/5167), by [@compulim](https://github.com/compulim)
 -  (Experimental) Added `<LocalizeString />` component which can be used to localize strings, by [@OEvgeny](https://github.com/OEvgeny) in PR [#5140](https://github.com/microsoft/BotFramework-WebChat/pull/5140)
 -  Added `<ThemeProvider>` component to apply theme pack to Web Chat, by [@compulim](https://github.com/compulim), in PR [#5120](https://github.com/microsoft/BotFramework-WebChat/pull/5120)
 -  Added `useMakeThumbnail` hook option to create a thumbnail from the file given, by [@compulim](https://github.com/compulim), in PR [#5123](https://github.com/microsoft/BotFramework-WebChat/pull/5123) and [#5122](https://github.com/microsoft/BotFramework-WebChat/pull/5122)

packages/fluent-theme/src/components/sendBox/AddAttachmentButton.module.css

@@ -1,10 +1,10 @@
 :global(.webchat-fluent) .sendbox__add-attachment {
-  display: grid
+  display: grid;
 }
 
 :global(.webchat-fluent) .sendbox__add-attachment-input {
   font-size: 0;
   height: 0;
   opacity: 0;
-  width: 0;
+  width: 1px; /* iOS Safari does not honor 0px for the width. */
 }