Fix Rails main compatibility: replace removed find_template with find

[Copilot]

ActionView::LookupContext#find_template was removed in Rails main — it was a long-deprecated alias for find. This caused 48 errors across the test suite when running against railsmain.gemfile.

Change

• lib/active_agent/concerns/view.rb: Replace lookup_context.find_template(...) with lookup_context.find(...) — identical signature, backward-compatible with Rails 7.2+.

# Before
template = lookup_context.find_template(template_name, _prefixes, false, [], **options)

# After
template = lookup_context.find(template_name, _prefixes, false, [], **options)