Create hmpps domain services alarms slack/pagerduty connection

[silvianahorga-al]

A reference to the issue / Description of it

Adding pagerduty integration for HMPPS Domain Services alarms

How does this PR fix the problem?

Makes sns topic hmpps_domain_services_prod_alarms and hmpps_domain_services_nonprod_alarms available for alarms to be sent to

How has this been tested?

Please describe the tests that you ran and provide instructions to reproduce.

Reproduces what's already working for nomis, csr, planetfm etc.

Deployment Plan / Instructions

Will this deployment impact the platform and / or services on it?

No

Checklist (check x in [ ] of list items)

• I have performed a self-review of my own code
• All checks have passed
• I have made corresponding changes to the documentation
• Plan and discussed how it should be deployed to PROD (If needed)

Additional comments (if any)

Will implement the sns topic part for alarms for hmpps-domain-services in the modernisation-platform-environments repo shortly

[github-actions]

Trivy Scan Success

Show Output

```hcl

---

Trivy will check the following folders:

</details> #### `Checkov Scan` Success
<details><summary>Show Output</summary>

```hcl

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Checkov will check the following folders:

CTFLint Scan Success

Show Output

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Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.5.0)
tflint will check the following folders:

Trivy Scan Success

Show Output

*****************************

Trivy will check the following folders:

[github-actions]

Trivy Scan Success

Show Output

```hcl

---

Trivy will check the following folders:

</details> #### `Checkov Scan` Success
<details><summary>Show Output</summary>

```hcl

*****************************

Checkov will check the following folders:

CTFLint Scan Success

Show Output

*****************************

Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.5.0)
tflint will check the following folders:

Trivy Scan Success

Show Output

*****************************

Trivy will check the following folders:

[github-actions]

Trivy Scan Success

Show Output

```hcl

---

Trivy will check the following folders:

</details> #### `Checkov Scan` Success
<details><summary>Show Output</summary>

```hcl

*****************************

Checkov will check the following folders:

CTFLint Scan Success

Show Output

*****************************

Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.5.0)
tflint will check the following folders:

Trivy Scan Success

Show Output

*****************************

Trivy will check the following folders:

[github-actions]

Trivy Scan Success

Show Output

```hcl

---

Trivy will check the following folders:

</details> #### `Checkov Scan` Success
<details><summary>Show Output</summary>

```hcl

*****************************

Checkov will check the following folders:

CTFLint Scan Success

Show Output

*****************************

Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.5.0)
tflint will check the following folders:

Trivy Scan Success

Show Output

*****************************

Trivy will check the following folders: