content: add last update to Viral Sequences section

layouts/partials/genomics/host-sequences-table.html

 <p>
   This section shows studies related to COVID-19 containing host sequences sequenced in Spain and archived in the European Genome-Phenome Archive (EGA).
-</p>
-<p>
+<br />
   Note that each study can include more than one dataset.
+<br />
+<br />
+These results are periodically manually retrieved from EGA.
 </p>
-<div class="alert alert-primary font-weight-bold border-0">
-  <i class="bi bi-exclamation-circle-fill"></i>
-  <span class="ml-2">These results are periodically manually retrieved from EGA.</span>
-</div>
 <p class="text-right">
   Powered by <a href="https://ega-archive.org/"><img src="{{ .Site.Params.images.logos.ega }}" alt="EGA" style="max-height: 3rem;"></a>
 </p>

layouts/partials/genomics/viral-sequences-table.html

 <p>
-  This section shows the samples sequenced from Severe acute respiratory syndrome coronavirus 2 (taxon: 2697049) in Spain. These results are periodically retrieved from ENA.
+  This section shows the samples sequenced from Severe acute respiratory syndrome coronavirus 2 (taxon: 2697049) in Spain.
+  <br />
+  These results are periodically retrieved from ENA.
 </p>
+<div class="d-flex">
+  {{ partial "last-update.html" (dict "context" . "last_update" (substr $.Site.Data.c19dpes_literature.timestamp 0 10)) }}
+</div>
 <p class="text-right">
   Powered by <a href="https://www.ebi.ac.uk/ena/browser/home"><img src="{{ .Site.Params.images.logos.ena }}" alt="ENA" style="max-height: 3rem;"></a>
 </p>