chore(helm): update image public.ecr.aws/bitnami/wordpress digest to c781f8a (#33011)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
|
[public.ecr.aws/bitnami/wordpress](https://redirect.github.com/bitnami/containers)
([source](https://redirect.github.com/bitnami/containers/tree/HEAD/bitnami/wordpress))
| digest | `bfca8ca` -> `c781f8a` |

Add the preset `:preserveSemverRanges` to your config if you don't want
to pin your dependencies.

---

### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined),
Automerge - At any time (no schedule defined).

🚦 **Automerge**: Enabled.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
this box

---

This PR has been generated by [Renovate
Bot](https://redirect.github.com/renovatebot/renovate).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzOS4xODguMyIsInVwZGF0ZWRJblZlciI6IjM5LjE4OC4zIiwidGFyZ2V0QnJhbmNoIjoibWFzdGVyIiwibGFiZWxzIjpbImF1dG9tZXJnZSIsInJlbm92YXRlL2NvbnRhaW5lciIsInR5cGUvZGlnZXN0Il19-->

charts/stable/wordpress/Chart.yaml

@@ -40,4 +40,4 @@ sources:
   - https://github.com/truecharts/charts/tree/master/charts/stable/wordpress
   - https://www.wordpress.org
 type: application
-version: 9.15.2
+version: 9.15.3

charts/stable/wordpress/values.yaml

@@ -1,7 +1,7 @@
 image:
   repository: public.ecr.aws/bitnami/wordpress
   pullPolicy: IfNotPresent
-  tag: 6.7.2@sha256:bfca8ca0d869b0ea58a3e1540de811cdc37be7106671b45bff801617b9abbe07
+  tag: 6.7.2@sha256:c781f8a24a09ef3cf2474403784539521b0762b09834017f1befd3826919026a
 securityContext:
   container:
     readOnlyRootFilesystem: false