fixed issue with disjunction that wouldnt resolve

Signed-off-by: Richard Jones <richard@dagger.io>

tests/tasks/gitPull/gitdir.cue

@@ -16,7 +16,7 @@ engine.#Plan & {
 		}
 
 		image: engine.#Pull & {
-			source: "alpine:3.15.0@sha256:e7d88de73db3d3fd9b2d63aa7f447a10fd0220b7cbf39803c803f2af9ba256b3"
+			source: "alpine:3.15.0"
 		}
 
 		verify: engine.#Exec & {
@@ -27,8 +27,8 @@ engine.#Plan & {
 				[ -d /repo2/.git ]
 				"""]
 			mounts: {
-				repo_1: {dest: "/repo1", contents: repo1.output}
-				repo_2: {dest: "/repo2", contents: repo2.output}
+				a: {dest: "/repo1", contents: repo1.output}
+				b: {dest: "/repo2", contents: repo2.output}
 			}
 		}