bpo-32096: Ensure new embedding test can find the encodings module (GH-4566)

diff --git a/Programs/_testembed.c b/Programs/_testembed.c
index 52a0b51..21aa76e 100644
--- a/Programs/_testembed.c
+++ b/Programs/_testembed.c
@@ -132,7 +132,8 @@
 
 static int test_pre_initialization_api(void)
 {
-    wchar_t *program = Py_DecodeLocale("spam", NULL);
+    /* Leading "./" ensures getpath.c can still find the standard library */
+    wchar_t *program = Py_DecodeLocale("./spam", NULL);
     if (program == NULL) {
         fprintf(stderr, "Fatal error: cannot decode program name\n");
         return 1;