Statically import MoreAsserts.assertThrows everywhere.

This will someday help us migrate to Junit's version.

PiperOrigin-RevId: 246368991
diff --git a/src/test/java/com/google/devtools/build/lib/actions/ArtifactTest.java b/src/test/java/com/google/devtools/build/lib/actions/ArtifactTest.java
index cc3587e..09bdf59 100644
--- a/src/test/java/com/google/devtools/build/lib/actions/ArtifactTest.java
+++ b/src/test/java/com/google/devtools/build/lib/actions/ArtifactTest.java
@@ -32,7 +32,6 @@
 import com.google.devtools.build.lib.skyframe.serialization.AutoRegistry;
 import com.google.devtools.build.lib.skyframe.serialization.ObjectCodecs;
 import com.google.devtools.build.lib.skyframe.serialization.testutils.SerializationTester;
-import com.google.devtools.build.lib.testutil.MoreAsserts;
 import com.google.devtools.build.lib.testutil.Scratch;
 import com.google.devtools.build.lib.vfs.FileSystem;
 import com.google.devtools.build.lib.vfs.Path;
@@ -297,7 +296,7 @@
   @Test
   public void testWeirdArtifact() throws Exception {
     Path execRoot = scratch.getFileSystem().getPath("/");
-    MoreAsserts.assertThrows(
+    assertThrows(
         IllegalArgumentException.class,
         () ->
             new Artifact(