theme: remove unused dynamic PHP scripts

On security request.

Note: Some of them are still referenced here and there.
But since PHP doesn't work anyway we can have them removed.
It doesn't change the outcome.

Signed-off-by: Jan Michalski <[email protected]>

Author: janekmi

themes/pmem-hugo/layouts/partials/head.html

@@ -58,8 +58,6 @@
   <!-- Bootstrap icon css -->
   <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/font/bootstrap-icons.css" type="text/css" />
 
-  <!-- Seo Demo Specific Stylesheet -->
-  <link rel="stylesheet" href="/css/colors.php?color=FE9603" type="text/css" />
   <!-- Theme Color -->
   <link rel="stylesheet" href="/css/template/fonts.css" type="text/css" />
   <link rel="stylesheet" href="/css/template/seo.css" type="text/css" />