Update to ACK runtime v0.56.0, code-generator v0.56.0 (#81)

### Update to ACK runtime `v0.56.0`, code-generator `v0.56.0`

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* ACK code-generator `v0.56.0` [release notes](https://github.com/aws-controllers-k8s/code-generator/releases/tag/v0.56.0)
* ACK runtime `v0.56.0` [release notes](https://github.com/aws-controllers-k8s/runtime/releases/tag/v0.56.0)

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NOTE:
This PR increments the release version of service controller from `v1.1.2` to `v1.2.0`

Once this PR is merged, release `v1.2.0` will be automatically created for `acm-controller`

**Please close this PR, if you do not want the new patch release for `acm-controller`**

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#### stdout for `make build-controller`:

```
building ack-generate ... ok.
==== building acm-controller ====
Copying common custom resource definitions into acm
Building Kubernetes API objects for acm
Generating deepcopy code for acm
Generating custom resource definitions for acm
Building service controller for acm
Running GO mod tidy
Generating RBAC manifests for acm
Running gofmt against generated code for acm
Updating additional GitHub repository maintenance files
==== building acm-controller release artifacts ====
Building release artifacts for acm-v1.2.0
Generating common custom resource definitions
Generating custom resource definitions for acm
Generating RBAC manifests for acm
```

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Author: ack-bot

.github/workflows/postsubmit.yaml

@@ -0,0 +1,10 @@
+name: Hydrate Go Proxy
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  call-hydrate-go-proxy:
+    uses: aws-controllers-k8s/.github/.github/workflows/reusable-postsubmit.yaml@main