feat: service dependency sync (#8)

### Description

This PR introduces support for service dependency syncing and
automatically creating Backstage integrations in PagerDuty for all new
mappings.

With these changes, we are reducing the manual effort on configuring
integration keys and service dependencies into Backstage configuration
files and ensuring they stay in-sync with PagerDuty.

**Issue number:** N/A

### Type of change

- [x] New feature (non-breaking change which adds functionality)
- [ ] Fix (non-breaking change which fixes an issue)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)

### Checklist

- [x] I have performed a self-review of this change
- [x] Changes have been tested
- [x] Changes are documented
- [x] Changes generate *no new warnings*
- [x] PR title follows [conventional commit
semantics](https://www.conventionalcommits.org/en/v1.0.0/)

If this is a breaking change 👇

- [ ] I have documented the migration process
- [ ] I have implemented necessary warnings (if it can live side by
side)

## Acknowledgement

By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice.

**Disclaimer:** We value your time and bandwidth. As such, any pull
requests created on non-triaged issues might not be successful.

backstage.json

@@ -1,3 +1,3 @@
 {
-  "version": "1.25.2"
+  "version": "1.29.2"
 }

package.json

@@ -31,21 +31,22 @@
     "postpack": "backstage-cli package postpack"
   },
   "dependencies": {
-    "@backstage/backend-common": "^0.21.6",
-    "@backstage/backend-defaults": "^0.2.16",
-    "@backstage/backend-plugin-api": "^0.6.20",
+    "@backstage/backend-common": "^0.23.3",
+    "@backstage/backend-defaults": "^0.4.1",
+    "@backstage/backend-plugin-api": "^0.7.0",
     "@backstage/catalog-model": "^1.5.0",
     "@backstage/config": "^1.2.0",
-    "@backstage/plugin-catalog-node": "^1.12.2",
-    "@pagerduty/backstage-plugin-common": "0.2.0",
+    "@backstage/plugin-catalog-common": "^1.0.25",
+    "@backstage/plugin-catalog-node": "^1.12.4",
+    "@pagerduty/backstage-plugin-common": "0.2.1",
     "@rjsf/core": "^5.14.3",
     "node-fetch": "^2.6.7",
     "winston": "^3.2.1",
     "yn": "^4.0.0",
     "zod": "^3.22.4"
   },
   "devDependencies": {
-    "@backstage/cli": "^0.24.0",
+    "@backstage/cli": "^0.26.11",
     "@types/node": "^20.9.2",
     "@types/node-fetch": "2.6.11",
     "@types/supertest": "^2.0.12",