Use the stable version of amqp on PHP 8.0+ (#472)

Test: amqp

MAINTAINERS.md

@@ -20,11 +20,6 @@ Once that draft release has been created, you have to:
 
 ## Extensions to be monitored
 
-### amqp
-
-For PHP 8+ we currenly install the `amqp` PHP extension with the `beta` stability.
-We should switch to `stable` when it will be available.
-
 ### cmark
 
 The `cmark` PHP extension requires the `libcmark` system library.

install-php-extensions

@@ -1983,9 +1983,7 @@ installRemoteModule() {
 	case "$installRemoteModule_module" in
 		amqp)
 			if test -z "$installRemoteModule_version"; then
-				if test $PHP_MAJMIN_VERSION -ge 800; then
-					installRemoteModule_version=beta
-				elif test "$DISTRO_VERSION" = debian@8; then
+				if test "$DISTRO_VERSION" = debian@8; then
 					# in Debian Jessie we have librabbitmq version 0.5.2
 					installRemoteModule_version=1.9.3
 				elif test $PHP_MAJMIN_VERSION -le 505; then