Activate January banner for PNSQC event (#842)

* Initial plan

* Activate January PNSQC banner with slideDown animation

Co-authored-by: ckenst <6896787+ckenst@users.noreply.github.com>

* Add accessibility and security improvements to banner link

Co-authored-by: ckenst <6896787+ckenst@users.noreply.github.com>

* Remove stray semicolon from CSS

Co-authored-by: ckenst <6896787+ckenst@users.noreply.github.com>

* Remove empty link element from banner

Co-authored-by: ckenst <6896787+ckenst@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: ckenst <6896787+ckenst@users.noreply.github.com>

Author: Copilot

_includes/banner.html

@@ -1,6 +1,5 @@
 <script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
 <script src="/assets/promo.js" type="text/javascript"></script>
-<link rel="stylesheet" type="text/css" />
 <div id="promo">
-  Do you have a software testing conference or workshop and want to list it? <a href="/how-to-contribute/">Learn how to contribute</a>.
+  Come Jam with PNSQC! <a href="https://mms.pnsqc.org/Calendar/moreinfo.php?org_id=PNSQ&amp;eventid=190750&amp;utm_source=testingconferences" rel="noopener" aria-label="Learn more about the PNSQC Jam event">Learn more</a>.
 </div>

_sass/_layout.scss

@@ -338,6 +338,7 @@
 }
 
 #promo {
+    display: none;
     position: relative;
     z-index: 101;
     top: 0;
@@ -350,7 +351,6 @@
         color: black;
     }
 
-    ;
     text-align: center;
     line-height: 1.5;
     font-weight: normal;