chore(all): release v0.30.0 (#614)

This commit will be tagged v0.30.0.

CHANGES.md

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@@ -1,3 +1,20 @@
+# v0.30.0
+
+## Changes
+
+- idtoken:
+  - Fix flaky ecdsa test.
+  - Fix some typos in the docs.
+  - Fix `WithCredentialsJSON` not working with `NewClient`.
+  - Speed up tests.
+- internal:
+  - Remove the install of staticcheck.
+  - Automate dependency updates with Renovate.
+- Various updates to autogenerated clients.
+
+_Please note:_ the release version is not indicative of an individual client's
+stability or version.
+
 # v0.29.0
 
 ## Changes