bug: Resolve "false" diff when generating pulumi preview

[ianaya89]

Some resources are showing "false" diff when running the pulumi up (even when the values were not updated)

Updating (dev)

View Live: https://app.pulumi.com/tnolet/checkly-pulumi-playground/dev/updates/22

     Type                                Name                           Status      Info
     pulumi:pulumi:Stack                 checkly-pulumi-playground-dev              1 message
 ~   ├─ checkly:index:MaintenanceWindow  my-maintenance-window          updated     [diff: ~endsAt,repeatEndsAt,startsAt]
 ~   ├─ checkly:index:Check              api-check                      updated     [diff: ~degradedResponseTime,maxResponseTime]
 ~   └─ checkly:index:Check              browser-check                  updated     [diff: ~degradedResponseTime,maxResponseTime]
 
Diagnostics:
  pulumi:pulumi:Stack (checkly-pulumi-playground-dev):
    {958 Daily maintenance 2022-03-01 2022-03-02 1 DAY 2022-03-02   []}
 
Resources:
    ~ 3 updated
    5 unchanged

Duration: 4s