Make Core extension civi_campaign a requirement
Now that the CiviCampaign component is a core extension (see this PR), it should be a requirement for Campaign Manager, I guess.
Otherwise code like this will not work due to missing API entities: https://lab.civicrm.org/extensions/campaignmanager/-/blob/2.x/Civi/Api4/Action/CampaignKPI/CalculateAll.php#L42
This requires to increase the minimum supported Core version to 5.64
at least, as the PR above was merged for that version.
Maybe this applies to other API entities as well (like Civi\Api4\Contribution
for code in https://lab.civicrm.org/extensions/campaignmanager/-/blob/2.x/Civi/CampaignManager/KPI/ContributionCountKPI.php#L23 or Civi\Api4\Membership
for code in https://lab.civicrm.org/extensions/campaignmanager/-/blob/2.x/Civi/CampaignManager/KPI/MembershipCountKPI.php#L23 - although those are kind of like plugins and would need their own requirement checks).