chore: remove changie (#79)

Author: fairclothjm

.changes/0.21.0.md

@@ -18,7 +18,6 @@ How was this change implemented?
 [Example](https://github.com/hashicorp/vault/commit/2715f5cec982aabc7b7a6ae878c547f6f475bba6)
 [ ] Add output for any tests not ran in CI to the PR description (eg, acceptance tests)
 [ ] Backwards compatible
-[ ] Changelog entry added. See [Updating the Changelog](https://github.com/hashicorp/vault-plugin-secrets-gcpkms/blob/main/README.md#updating-the-changelog).
 
 ## PCI review checklist
 

.changes/unreleased/.gitkeep

@@ -133,41 +133,3 @@ against a production project!
 [kms]: https://cloud.google.com/kms
 [vault]: https://www.vaultproject.io
 
-## Updating the Changelog
-
-All pull requests that introduce a user-facing change must include a changelog
-entry. We use the [changie](https://changie.dev/) tool to manage these entries
-and automate the release process.
-
----
-### 1. Installing Changie
-
-You only need to do this once. If you don't have `changie` installed, choose one of the options below.
-
-* **Homebrew** (macOS):
-    ```shell
-    brew install changie
-    ```
-* **Go Install**:
-    ```shell
-    go install github.com/miniscruff/changie@latest
-    ```
-* **Other Methods**:
-  See the [official changie installation guide](https://changie.dev/guide/installation/) for other options, including pre-compiled binaries.
-
----
-### 2. Creating an Entry
-
-Once your code changes are complete, create the changelog entry:
-
-1.  **Run the command** in your terminal:
-    ```shell
-    changie new
-    ```
-2.  **Follow the prompts.** An interactive prompt will ask you to select the
-    kind of change (e.g., `BREAKING CHANGES`, `NOTES`, `FEATURES`) and write a concise description of
-    what you changed.
-
-3.  **Commit the new file.** After you're done, `changie` will create a new
-    YAML file in the `.changie/unreleased` directory. Commit this file along with your other
-    code changes before submitting your pull request.