[welcome] check for yad existence

welcome/PKGBUILD

@@ -2,7 +2,7 @@
 
 pkgname=welcome
 pkgdesc="Welcome greeter for new EndeavourOS users."
-pkgver=24.6
+pkgver=24.7
 pkgrel=1
 arch=('any')
 license=('GPL')
@@ -39,7 +39,7 @@ source=(
   $_url/eos-install-mode-run-calamares
   $_url/arm-eos-welcome-installer
 )
-sha512sums=('dc0caf264b470edd8bd0cdab9bd902c2aae96418f3bfd3b37e5b848eb75f207a236c6df7cff92d4b2f7539ae56986255ff3fc92b39b75f5abeeb14186bdb53a8'
+sha512sums=('18215465311e97b8fa3bac27205154058c3f05d42d1616e735ef69026c50b2432539113e15f81898ca23c9ea5a23ee301253f6a176d9f1b4fbebf37c5be87393'
             'f8d3042f672b8f3b0fd409d8ed5922704737172414af42ea87c588cc8fd5970b05dc7954abb56b4139370cefb99d187c90272e48e34346a072f22bdb52624919'
             '36dcdd5db1d86b88a87c4e48b718b0986107980fc289dd8dd643a365508255a81680d197442dfe6933bbb8b06e2ccc7d7b55bf28ce1a925cdfd0278c6fee2c7f'
             '5ca4b7108573a980d9d4011c5afde4f459abe8e36f5b6bc846368dcc48cfa2e672133f074fdeac4282835fa5b87f7afb2cd9dc3e985b4d2e8f574ac239c90ba2'