build: remove vaadin-snapshots repository

Author: javier-godoy

pom.xml

@@ -85,11 +85,6 @@
             <id>Vaadin prereleases</id>
             <url>https://maven.vaadin.com/vaadin-prereleases</url>
         </repository>
-        <!-- Repository needed for the snapshot versions of Vaadin -->
-        <repository>
-            <id>vaadin-snapshots</id>
-            <url>https://oss.sonatype.org/content/repositories/vaadin-snapshots/</url>
-        </repository>
         <!-- Flowing Code Repository -->
         <repository>
             <id>flowing-releases</id>