osbase/test/ktest: fix transitions

Only executables which are executed with ctx.actions.run should be
transitioned to exec cfg; those which are executed while the test runs
should be left as target cfg.

This misconfiguration caused the //osbase/test/ktest:linux-testing
kernel to be built twice, once for exec and once for target. This is now
fixed.

Before:
bazel cquery "deps(//...) intersect //osbase/test/ktest:linux-testing"
//osbase/test/ktest:linux-testing (090513b)
//osbase/test/ktest:linux-testing (0f84b2e)

After:
bazel cquery "deps(//...) intersect //osbase/test/ktest:linux-testing"
//osbase/test/ktest:linux-testing (090513b)

Change-Id: I23441a327f2246c308623e425ca66b79064c51a5
Reviewed-on: https://review.monogon.dev/c/monogon/+/4155
Reviewed-by: Tim Windelschmidt <tim@monogon.tech>
Tested-by: Jenkins CI
diff --git a/osbase/test/ktest/ktest.bzl b/osbase/test/ktest/ktest.bzl
index c7ecf59..2d8fd91 100644
--- a/osbase/test/ktest/ktest.bzl
+++ b/osbase/test/ktest/ktest.bzl
@@ -56,7 +56,7 @@
 k_test = rule(
     implementation = _ktest_impl,
     doc = """
-        Run a given test program under the Monogon kernel. 
+        Run a given test program under the Monogon kernel.
     """,
     attrs = {
         "tester": attr.label(
@@ -103,7 +103,6 @@
         ),
         "kernel": attr.label(
             default = Label("//osbase/test/ktest:linux-testing"),
-            cfg = "exec",
             allow_single_file = True,
         ),
         "cmdline": attr.string(
@@ -112,7 +111,7 @@
         # Tool
         "_ktest": attr.label(
             default = Label("//osbase/test/ktest"),
-            cfg = "exec",
+            cfg = "target",
             executable = True,
             allow_files = True,
         ),