MDL-67265 core: Set max-height on toast wrapper

theme/boost/scss/moodle/core.scss

@@ -2411,6 +2411,7 @@ $picker-emojis-per-row: 7 !default;
 
 .toast-wrapper {
     max-width: $toast-max-width;
+    max-height: 0;
     // Place these above any modals and other elements.
     z-index: 1051;
 }

theme/boost/style/moodle.css

@@ -11567,6 +11567,7 @@ body.h5p-embed .h5pmessages {
 
 .toast-wrapper {
   max-width: 350px;
+  max-height: 0;
   z-index: 1051; }
 
 .icon {

theme/classic/style/moodle.css

@@ -11822,6 +11822,7 @@ body.h5p-embed .h5pmessages {
 
 .toast-wrapper {
   max-width: 350px;
+  max-height: 0;
   z-index: 1051; }
 
 .icon {