Add CanceledAt, RunEvents, and TriggerReason to Run

[ctrombley]

Description

This PR adds CanceledAt, RunEvents, TriggerReason fields to Run struct, originally by @jpadrianoGo (#1161).

Testing plan

1. Generate the required environment variables for go test, TFE_ADDRESS and TFE_TOKEN
2. Run TFE_ADDRESS="https://example" TFE_TOKEN="example" go test ./... -v -run TestRunsCanceledAt. The new tests should pass.
3. CanceledAt, RunEvents, TriggerReason is read for Run.

{
  "data": {
    "id": "run-***",
    "type": "runs",
    "attributes": {
      "actions": {
        "is-cancelable": false,
        "is-confirmable": false,
        "is-discardable": false,
        "is-force-cancelable": false
      },
      "allow-config-generation": false,
      "allow-empty-apply": false,
      "auto-apply": false,
      "canceled-at": "2025-07-21T08:42:10.617Z",
      "created-at": "2025-07-21T08:42:10.116Z",
      "has-changes": false,
      "is-destroy": false,
      "message": "Triggered via API",
      "plan-only": false,
      "refresh": true,
      "refresh-only": false,
      "replace-addrs": null,
      "save-plan": false,
      "source": "tfe-api",
      "status-timestamps": {
        "force-canceled-at": "2025-07-21T08:42:10+00:00"
      },
      "status": "canceled",
      "target-addrs": null,
      "trigger-reason": "manual",
      "terraform-version": "1.12.2",
      "updated-at": "2025-07-21T08:42:10.673Z",
      "permissions": {
        "can-apply": true,
        "can-cancel": true,
        "can-comment": true,
        "can-discard": true,
        "can-force-execute": true,
        "can-force-cancel": true,
        "can-override-policy-check": true
      },
      "variables": [],
      "force-cancel-available-at": "2025-07-21T08:43:10.617Z"
    },
    "relationships": {
      "workspace": {
        "data": {
          "id": "ws-***",
          "type": "workspaces"
        }
      },
      "apply": {
        "data": {
          "id": "apply-***",
          "type": "applies"
        },
        "links": {
          "related": "/api/v2/runs/run-***/apply"
        }
      },
      "canceled-by": {
        "data": {
          "id": "user-***",
          "type": "users"
        },
        "links": {
          "related": "/api/v2/runs/run-***/canceled-by"
        }
      },
      "configuration-version": {
        "data": {
          "id": "cv-***",
          "type": "configuration-versions"
        },
        "links": {
          "related": "/api/v2/runs/run-***/configuration-version"
        }
      },
      "created-by": {
        "data": {
          "id": "user-***",
          "type": "users"
        },
        "links": {
          "related": "/api/v2/runs/run-***/created-by"
        }
      },
      "plan": {
        "data": {
          "id": "plan-***",
          "type": "plans"
        },
        "links": {
          "related": "/api/v2/runs/run-***/plan"
        }
      },
      "run-events": {
        "data": [
          {
            "id": "re-***",
            "type": "run-events"
          },
          {
            "id": "re-***",
            "type": "run-events"
          },
          {
            "id": "re-***",
            "type": "run-events"
          }
        ],
        "links": {
          "related": "/api/v2/runs/run-***/run-events"
        }
      },
      "task-stages": {
        "data": [],
        "links": {
          "related": "/api/v2/runs/run-***/task-stages"
        }
      },
      "policy-checks": {
        "data": [],
        "links": {
          "related": "/api/v2/runs/run-***/policy-checks"
        }
      },
      "comments": {
        "data": [],
        "links": {
          "related": "/api/v2/runs/run-***/comments"
        }
      }
    },
    "links": {
      "self": "/api/v2/runs/run-***"
    }
  }
}

External links

Output from tests

Including output from tests may require access to a TFE instance. Ignore this section if you have no environment to test against.

$ TFE_ADDRESS="https://example" TFE_TOKEN="example"go test ./... -v -run TestRunsCanceledAt 

=== RUN   TestRunsCanceledAt
=== RUN   TestRunsCanceledAt/when_the_run_is_not_canceled
=== RUN   TestRunsCanceledAt/when_the_run_is_canceled
--- PASS: TestRunsCanceledAt (10.00s)
    --- PASS: TestRunsCanceledAt/when_the_run_is_not_canceled (0.38s)
    --- PASS: TestRunsCanceledAt/when_the_run_is_canceled (0.91s)
PASS
ok      github.com/hashicorp/go-tfe     10.059s

$ TFE_ADDRESS="https://example" TFE_TOKEN="example"go test ./... -v -run TestRunsRunEvents 

go test -run TestRunsRunEvents -v
=== RUN   TestRunsRunEvents
--- PASS: TestRunsRunEvents (4.86s)
PASS
ok      github.com/hashicorp/go-tfe     4.908s

$ TFE_ADDRESS="https://example" TFE_TOKEN="example"go test ./... -v -run TestRunsTriggerReason
=== RUN   TestRunsTriggerReason
--- PASS: TestRunsTriggerReason (5.01s)
PASS
ok      github.com/hashicorp/go-tfe     5.104s

[github-actions]

Reminder to the contributor that merged this PR: if your changes have added important functionality or fixed a relevant bug, open a follow-up PR to update CHANGELOG.md with a note on your changes.