TLDR; Awaiting a new Devise release after the previous v4.9.2.
A warning may appear when running Rails 7.1 with Devise:
DeprecatedConstantAccessor.deprecate_constant without a deprecator is deprecated
Rails deprecated the use of
ActiveSupport::Deprecation as a singleton, and requires gems to use their own deprecator objects.
The necessary change has been merged into Devise, but is pending a new release of the library after the previous version 4.9.2.
Other gems may have the same issue, so the warning could appear if not using Devise. (Advice is to check for repo issues created by other users.)