chore: bump digitalocean/digitalocean in /infra/terraform

Bumps [digitalocean/digitalocean](https://github.com/digitalocean/terraform-provider-digitalocean) from 2.50.0 to 2.51.0.
- [Release notes](https://github.com/digitalocean/terraform-provider-digitalocean/releases)
- [Changelog](https://github.com/digitalocean/terraform-provider-digitalocean/blob/main/CHANGELOG.md)
- [Commits](digitalocean/terraform-provider-digitalocean@v2.50.0...v2.51.0)

---
updated-dependencies:
- dependency-name: digitalocean/digitalocean
  dependency-version: 2.51.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

infra/terraform/.terraform.lock.hcl

@@ -4,7 +4,7 @@ terraform {
   required_providers {
     digitalocean = {
       source  = "digitalocean/digitalocean"
-      version = "2.50.0"
+      version = "2.51.0"
     }
     uptimerobot = {
       source  = "vexxhost/uptimerobot"