Add missing a11y label to dismiss onboarding button in room list (#12587)

* Add a11y label to dismiss onboarding button in room list

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Iterate

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Iterate

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

---------

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/components/views/user-onboarding/UserOnboardingButton.tsx

@@ -76,7 +76,11 @@ function UserOnboardingButtonInternal({ selected, minimized }: Props): JSX.Eleme
                         <Heading size="4" className="mx_Heading_h4">
                             {_t("common|welcome")}
                         </Heading>
-                        <AccessibleButton className="mx_UserOnboardingButton_close" onClick={onDismiss} />
+                        <AccessibleButton
+                            className="mx_UserOnboardingButton_close"
+                            onClick={onDismiss}
+                            aria-label={_t("action|dismiss")}
+                        />
                     </div>
                 </>
             )}