Don't let status messages shrink form buttons

When a form status message is displayed (often an error), it could cause
the button to be shrunk, making it look strange (sometimes the text
would even become larger than the button background). This prevents it
from being able to shrink and will cause the message to wrap instead.

tildes/scss/modules/_form.scss

@@ -38,6 +38,7 @@ select.form-select:not([multiple]) {
 
   button {
     margin-left: 0.4rem;
+    flex-shrink: 0;
   }
 }