SLE-1463 Update SonarPython analyzer to 5.21.0.32726

Author: Krosovok

org.sonarlint.eclipse.core/pom.xml

@@ -99,7 +99,7 @@
                 <artifactItem>
                   <groupId>org.sonarsource.python</groupId>
                   <artifactId>sonar-python-plugin</artifactId>
-                  <version>5.20.0.32295</version>
+                  <version>5.21.0.32726</version>
                   <type>jar</type>
                 </artifactItem>
                 <artifactItem>

org.sonarlint.eclipse.ui/intro/RELEASE_NOTES.html

@@ -19,11 +19,12 @@ <h1>{VERSION}</h1>
 -->
 
 <div>
-    <h1>12.0</h1>
+    <h1>12.1</h1>
     <p>
         See the <a href="https://github.com/SonarSource/sonarlint-eclipse/releases">GitHub Release page</a>
     </p>
     <ul>
+        <li>Update Python analyzer -> 5.21</li>
         <li>Update JS/TS/CSS analyzer -> <a href="https://github.com/SonarSource/SonarJS/releases/tag/12.3.0.39932">12.3</a></li>
     </ul>
 </div>