Make the WooPay button relative to contain the spinner (#11127)

Author: RadoslavGeorgiev

changelog/woopmnt-5398-woopay-button-spinner-and-label-is-not-visible-on-click

@@ -0,0 +1,4 @@
+Significance: minor
+Type: fix
+
+Fix styling of the WooPay button to make sure that the spinner is visible when loading.

client/checkout/woopay/express-button/style.scss

@@ -18,6 +18,7 @@
 		text-transform: none;
 		list-style-type: none;
 		min-height: auto;
+		position: relative;
 
 		.button-content {
 			display: flex;