cue files: #compute -> #up

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

tests/compute/success/noop/main.cue

@@ -2,5 +2,5 @@ package testing
 
 // no-op, should not error
 empty: {
-	#compute: []
+	#up: []
 }

tests/compute/success/overload/flat/main.cue

@@ -6,7 +6,7 @@ new_prop: "lala"
 new_prop_too: string
 #new_def_too: string
 
-#compute: [{
+#up: [{
 	do:  "fetch-container"
 	ref: "busybox"
 },

tests/compute/success/overload/wrapped/main.cue

@@ -7,7 +7,7 @@ foo: {
 	new_prop_too: string
 	#new_def_too: string
 
-	#compute: [{
+	#up: [{
 		do:  "fetch-container"
 		ref: "busybox"
 	},

tests/compute/success/simple/main.cue

@@ -1,6 +1,6 @@
 package testing
 
-#compute: [
+#up: [
 	{
 		do:  "fetch-container"
 		ref: "busybox"