tests: gpio_basic_api: fix filter to exclude boards without overlay

The test case no longer permits inferring input and output pins based
only on the presence of GPIO aliases.  Stop allowing presence of GPIO
aliases to enable the test.

Signed-off-by: Peter Bigot <[email protected]>

Author: pabigot

tests/drivers/gpio/gpio_basic_api/testcase.yaml

@@ -4,5 +4,4 @@ tests:
     depends_on: gpio
     harness: console
     min_flash: 34
-    filter: dt_compat_enabled("test,gpio_basic_api") or
-            dt_alias_exists("gpio-0") or dt_alias_exists("gpio-1")
+    filter: dt_compat_enabled("test,gpio_basic_api")