[Techniques] remove external highlight.js (#4520)

Remove unnecessary `<link>` and `<script>` tags.

Co-authored-by: Patrick H. Lauke <[email protected]>
Co-authored-by: Mike Gower <[email protected]>

Author: 3 people

techniques/client-side-script/SCR14.html

@@ -101,7 +101,4 @@ <h3>Expected Results</h3>
          </ul>
       </section>
    </section>
-	 <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.7.0/styles/default.min.css">
-	 <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.7.0/highlight.min.js"></script>
-	 <script>hljs.highlightAll();</script>	 
 </body></html>

techniques/css/C13.html

@@ -69,6 +69,5 @@ <h2>Resources</h2>
 						</li>
 					</ul>
 				</section>
-<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.7.0/styles/default.min.css"> <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.7.0/highlight.min.js"></script> <script>hljs.highlightAll();</script>
 </body>
 </html>

techniques/css/C15.html

@@ -120,6 +120,5 @@ <h2>Resources</h2>
 				</li>
 			</ul>
 		</section>
-<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.7.0/styles/default.min.css"> <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.7.0/highlight.min.js"></script> <script>hljs.highlightAll();</script>
 </body>
 </html>

techniques/css/C18.html

@@ -60,6 +60,5 @@ <h2>Resources</h2>
 						</li>
          </ul>
 				</section>
-<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.7.0/styles/default.min.css"> <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.7.0/highlight.min.js"></script> <script>hljs.highlightAll();</script>
 </body>
 </html>