testing/php7-pecl-grpc: disable on riscv64

testing/php7-pecl-grpc/APKBUILD

@@ -5,7 +5,7 @@ pkgver=1.34.0
 pkgrel=0
 pkgdesc="PHP extension provide a concrete implementation of the gRPC protocol, layered over HTTP/2."
 url="https://pecl.php.net/package/grpc"
-arch="all !s390x !ppc64le !armv7 !armhf" # armv7, armhf, ppc64le: build failures
+arch="all !s390x !ppc64le !armv7 !armhf !riscv64" # armv7, armhf, ppc64le: build failures
 license="Apache-2.0"
 depends="php7-common"
 makedepends="php7-dev openssl-dev linux-headers"