[libc][bazel] Minor cleanup to remove unused dependencies.

* strcpy doesn't need to depend on memcpy
* qsort_test_helper has been generalized and doesn't need to depend on
  qsort.

This is a small cleanup to unblock the work outlined in #130327.

Author: vonosmas

libc/test/src/stdlib/SortingTest.h

@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/__support/macros/config.h"
-#include "src/stdlib/qsort.h"
 #include "test/UnitTest/Test.h"
 
 class SortingTest : public LIBC_NAMESPACE::testing::Test {

utils/bazel/llvm-project-overlay/libc/BUILD.bazel

@@ -4270,7 +4270,6 @@ libc_function(
     hdrs = ["src/string/strcpy.h"],
     deps = [
         ":__support_common",
-        ":memcpy",
         ":string_memory_utils",
         ":string_utils",
     ],

utils/bazel/llvm-project-overlay/libc/test/src/stdlib/BUILD.bazel

@@ -115,7 +115,6 @@ libc_support_library(
     hdrs = ["SortingTest.h"],
     deps = [
         "//libc:__support_macros_config",
-        "//libc:qsort",
         "//libc/test/UnitTest:LibcUnitTest",
     ],
 )