Remove unnecessary test.

httpcore5/src/test/java/org/apache/hc/core5/http/TestContentType.java

@@ -300,15 +300,4 @@ void testFormUrlEncodedWithoutCharset() throws Exception {
         final String redirectedBody = "echotext=TEST%F6TEST";
         Assertions.assertEquals(encodedBody, redirectedBody);  // Ensure body stays the same after redirect
     }
-
-    @Test
-    void testImplicitCharsetForApplicationJson() throws Exception {
-        // ContentType for application/json with implicitCharset = true
-        final ContentType contentType = ContentType.create("application/json", StandardCharsets.UTF_8, true);
-
-        // Check that the charset is not added to the toString() output
-        Assertions.assertEquals("application/json", contentType.toString());
-        // Check that the charset is still stored
-        Assertions.assertEquals(StandardCharsets.UTF_8, contentType.getCharset());
-    }
 }