Remove the temporary gate probe

Confirmed: the run failed at the Test step and the registry digest was unchanged, so a
failing test now stops the image being published.

src/test/java/com/itsthevine/web/GateProbeTest.java

@@ -1,14 +0,0 @@
-package com.itsthevine.web;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-import org.junit.jupiter.api.Test;
-
-/** TEMPORARY: proves a failing test actually stops the image being published. Removed immediately. */
-class GateProbeTest {
-
-    @Test
-    void deliberatelyFails() {
-        assertThat("the gate").isEqualTo("proved");
-    }
-}