Update dc-api.md ro remove mediation: "required"

After w3c-fedid/digital-credentials#392, mediation doesn't need to be specified.

Author: mohamedamir

docs/requesting-credential/dc-api.md

@@ -28,7 +28,6 @@ async function requestCredential() {
       // Call the Digital Credentials API using the presentation request from the backend
       let dcResponse = await navigator.credentials.get({
         signal: controller.signal,
-        mediation: "required",
         digital: {
           requests: [{
             protocol: "openid4vp",
@@ -67,4 +66,4 @@ async function requestCredential() {
 
 ## Android Native
 
-## Fallback
+## Fallback