Bump shard counts for qs8_gemm_minmax_rndnu_test, the test sometimes timeout in coverage runs.

PiperOrigin-RevId: 421060558
diff --git a/BUILD.bazel b/BUILD.bazel
index 3139627..5192c63 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -11558,6 +11558,7 @@
         "test/qs8-gemm-minmax-rndnu-4.cc",
         "test/qs8-gemm-minmax-rndnu-5.cc",
     ] + WEIGHTS_PACK_HDRS + MICROKERNEL_TEST_HDRS,
+    shard_count = 10,
     deps = MICROKERNEL_TEST_DEPS + [
         ":jit",
         ":gemm_microkernel_tester",