web: ensure img tags have alt attributes

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

web/src/flow/FlowExecutor.ts

@@ -501,6 +501,7 @@ export class FlowExecutor extends AKElement implements StageHost {
                                             <div class="pf-c-brand ak-brand">
                                                 <img
                                                     src="${first(this.tenant?.brandingLogo, "")}"
+                                                    alt="authentik Logo"
                                                 />
                                             </div>
                                         </header>

web/src/flow/stages/authenticator_duo/AuthenticatorDuoStage.ts

@@ -86,7 +86,7 @@ export class AuthenticatorDuoStage extends BaseStage<
                             >
                         </div>
                     </ak-form-static>
-                    <img src=${this.challenge.activationBarcode} />
+                    <img src=${this.challenge.activationBarcode} alt=${t`Duo activation QR code`} />
                     <p>
                         ${t`Alternatively, if your current device has Duo installed, click on this link:`}
                     </p>