Shard bazel_module_test and py_test

Try to avoid
```
//src/test/py/bazel:bazel_module_test                                  TIMEOUT in 3
out of 3 in 900.1s
//src/test/py/bazel:py_test                                             TIMEOUT in 3 out of 3 in 300.1s
```
in Bazel postsubmit

PiperOrigin-RevId: 519149009
Change-Id: I7a761f85fdf1e2622571b6547686225297091d5a

src/test/py/bazel/BUILD

@@ -65,6 +65,7 @@ py_test(
     name = "py_test",
     size = "medium",
     srcs = ["py_test.py"],
+    shard_count = 5,
     deps = [":test_base"],
 )
 
@@ -267,6 +268,7 @@ py_test(
     name = "bazel_module_test",
     size = "large",
     srcs = ["bzlmod/bazel_module_test.py"],
+    shard_count = 5,
     tags = [
         "requires-network",
     ],