port Bazel //tools/autograd to shared build structure

Pull Request resolved: #74749

Differential Revision: [D35145072](https://our.internmc.facebook.com/intern/diff/D35145072/)

**NOTE FOR REVIEWERS**: This PR has internal Facebook specific changes or comments, please review them on [Phabricator](https://our.internmc.facebook.com/intern/diff/D35145072/)!

Approved by: https://github.com/albanD

Author: Michael Andreas Dagitses

tools/autograd/BUILD.bazel

@@ -1,10 +1,4 @@
-py_library(
-    name = "autograd",
-    srcs = glob(["*.py"]),
-    data = glob([
-        "*.yaml",
-        "templates/*",
-    ]),
-    visibility = ["//:__subpackages__"],
-    deps = ["//tools/codegen"],
-)
+load("//:tools/bazel.bzl", "rules")
+load(":build.bzl", "define_targets")
+
+define_targets(rules = rules)

tools/autograd/build.bzl

@@ -0,0 +1,14 @@
+def define_targets(rules):
+    rules.py_library(
+        name = "autograd",
+        srcs = rules.glob(["*.py"]),
+        data = rules.glob([
+            "*.yaml",
+            "templates/*",
+        ]),
+        visibility = ["//:__subpackages__"],
+        deps = [
+            rules.requirement("PyYAML"),
+            "//tools/codegen",
+        ],
+    )