topdown: fix partial-eval test rejected by new conflict check

The 'partial set, general ref head' shallow-inlining test paired a set
rule (p.q contains x) with an object-of-sets rule (p.q[r].s contains t)
sharing the name p.q. That is exactly the set-vs-object conflict this
change now rejects at compile time, and it panics at eval time on main,
so the fixture is itself an invalid policy.

Replace it with a single general-ref partial-set rule that keeps the
shallow-inlining full-extent path under test, and update the expected
support module.

Signed-off-by: Sebastian Spaink <sebastianspaink@gmail.com>

v1/topdown/topdown_partial_test.go

@@ -1507,14 +1507,12 @@ func TestTopDownPartialEval(t *testing.T) {
 			modules: []string{
 				`package test
 				import future.keywords.contains
-				p.q contains x if { input.x = x }
 				p.q[r].s contains t if { input.r = r; input.t = t }`,
 			},
 			wantQueries: []string{`data.partial.test.p.q = x`},
 			wantSupport: []string{`
 				package partial.test.p
 				import future.keywords.contains
-				q contains x2 if  { input.x = x2 }
 				q[r1].s contains t1 if { input.r = r1; input.t = t1 }
 			`},
 		},