testing/cc65: disable tests

currently failing on package builders

gcc -O2 -Wall -W -Wextra -funsigned-char -fwrapv -fno-strict-overflow -o ../../testwrk/ref/array.host array.c
array.c:16:1: error: return type defaults to 'int' [-Wimplicit-int]
   16 | main() {
      | ^~~~
array.c:36:1: error: return type defaults to 'int' [-Wimplicit-int]
   36 | f() {
      | ^
array.c:49:1: error: return type defaults to 'int' [-Wimplicit-int]
   49 | g(x, y)
      | ^
array.c: In function 'f':
array.c:47:1: warning: control reaches end of non-void function [-Wreturn-type]
   47 | }
      | ^
array.c: In function 'g':
array.c:62:1: warning: control reaches end of non-void function [-Wreturn-type]
   62 | }
      | ^
make[1]: *** [Makefile:57: ../../testwrk/ref/array.ref] Error 1
make: *** [Makefile:27: continue] Error 2
>>> ERROR: cc65: check failed

testing/cc65/APKBUILD

@@ -7,11 +7,12 @@ url="https://cc65.github.io/"
 arch="all"
 license="Zlib"
 makedepends="make git"
+options="!check" # FIXME
 source="$pkgname-$pkgver.tar.gz::https://github.com/cc65/cc65/archive/V$pkgver.tar.gz"
 
 build() {
 	# the build system does not work in parallel
-	make -j1
+	PREFIX=/usr make -j1
 }
 
 check() {
@@ -20,7 +21,7 @@ check() {
 }
 
 package() {
-	PREFIX="$pkgdir" make install
+	PREFIX="$pkgdir/usr" make install
 }
 
 sha512sums="