Remove redundant RunAt field from CAAData

The observation timestamp is already stored by the core; there is no
need to duplicate it inside the payload.

checker/collect.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"time"
 
 	sdk "git.happydns.org/checker-sdk-go/checker"
 )
@@ -64,7 +63,6 @@ func (p *caaProvider) Collect(ctx context.Context, opts sdk.CheckerOptions) (any
 	return &CAAData{
 		Domain:  domain,
 		Records: records,
-		RunAt:   time.Now().UTC().Format(time.RFC3339),
 	}, nil
 }
 

checker/types.go

@@ -40,7 +40,6 @@ const (
 type CAAData struct {
 	Domain  string      `json:"domain,omitempty"`
 	Records []CAARecord `json:"records,omitempty"`
-	RunAt   string      `json:"run_at,omitempty"`
 }
 
 type CAARecord struct {