fix: release note indentation

[Diaphteiros]

What this PR does / why we need it:
Fixes the release note indentation. See below for examples.

Which issue(s) this PR fixes:
None

Special notes for your reviewer:
The release note

The validation for the `spec.iam.oidcProviders` field in the `ManagedControlPlaneV2` resource has been changed in multiple ways:
- `usernamePrefix` and `groupsPrefix` have been removed and are now always assumed to be `<name>:`
- `name` is not allowed to be set to `system` (prevents k8s service account impersonation)
- The regex validation rule for `name` has been fixed
- `issuer` and `clientID` are now required and the former one must look like an URL
- Duplicate OIDC provider names or ones that clash with the default OIDC provider are now prevented

was previously rendered as the following in the generated changelog (enclosed in horizontal lines for better visibility)

---

• <PR_HEADER>:
  • The validation for the spec.iam.oidcProviders field in the ManagedControlPlaneV2 resource has been changed in multiple ways:
• usernamePrefix and groupsPrefix have been removed and are now always assumed to be <name>:
• name is not allowed to be set to system (prevents k8s service account impersonation)
• The regex validation rule for name has been fixed
• issuer and clientID are now required and the former one must look like an URL
• Duplicate OIDC provider names or ones that clash with the default OIDC provider are now prevented

---

and is now correctly rendered as

---

• <PR_HEADER>:
  • The validation for the spec.iam.oidcProviders field in the ManagedControlPlaneV2 resource has been changed in multiple ways:
    • usernamePrefix and groupsPrefix have been removed and are now always assumed to be <name>:
    • name is not allowed to be set to system (prevents k8s service account impersonation)
    • The regex validation rule for name has been fixed
    • issuer and clientID are now required and the former one must look like an URL
    • Duplicate OIDC provider names or ones that clash with the default OIDC provider are now prevented

---

Release note:

Fixed a bug that caused multiline release notes to be wrongly indented in the generated changelog.