Remove OpenNebula from support providers

Page does not mention Prometheus; OpenNebula is a platform not a support provider.

Signed-off-by: Bryan Boreham <[email protected]>

Author: bboreham

content/support-training.html

@@ -120,12 +120,6 @@ <h2>Commercial support</h2>
             </a>
           </div>
 
-          <div class="col-md-3 col-sm-6 doc-content tc-col">
-            <a href="https://opennebula.io" class="btn btn-training btn-default btn-large" target="_blank">
-              <img src="../assets/commercial-support-logos/opennebula.svg" alt="OpenNebula">
-            </a>
-          </div> 
-          
           <div class="col-md-3 col-sm-6 doc-content tc-col">
               <a href="https://o11y.eu/prometheus-support/" class="btn btn-training btn-default btn-large" target="_blank">
                 <img src="../assets/commercial-support-logos/o11y.svg" alt="O11y">