Format sponsor logos so they work regardless of light/dark mode.

Author: dpage

media/css/main.css

@@ -1779,6 +1779,12 @@ img.organisation-logo {
   max-height: 65px;
   max-width: 150px;
 }
+th.organisation-logo {
+  height: 65px;
+  width: 150px;
+  background-color: white !important;
+  text-align: center;
+}
 
 /** Release Notes */
 #release-notes .navheader,

templates/sponsors/contributing.html

@@ -20,7 +20,7 @@ <h2>{{ sponsor.sponsortype.typename }}</h2>
       <tbody>
         {% endifchanged%}
           <tr>
-            <th scope="row">
+            <th scope="row" class="organisation-logo">
               <a href="{{ sponsor.url }}" target="_blank" rel="noopener">
                 <img class="organisation-logo" src="/media/img/about/sponsors/{{ sponsor.logoname }}" alt="{{ sponsor.name }}" />
               </a>

templates/sponsors/financial.html

@@ -70,7 +70,7 @@ <h3>PostgreSQL Community Association Sponsors</h3>
   </thead>
   <tbody>
     <tr>
-      <th scope="row">
+      <th scope="row" class="organisation-logo">
         <a href="https://aws.amazon.com" target="_blank" rel="noopener">
           <img class="organisation-logo" src="/media/img/about/sponsors/logo_aws.svg" alt="AWS" />
         </a>
@@ -80,7 +80,7 @@ <h3>PostgreSQL Community Association Sponsors</h3>
       <td>Benefactor</td>
     </tr>
     <tr>
-      <th scope="row">
+      <th scope="row" class="organisation-logo">
         <a href="https://xata.io" target="_blank" rel="noopener">
           <img class="organisation-logo" src="/media/img/about/sponsors/logo_xata.svg" alt="Xata" />
         </a>