Add warning to templates using the classic parameters to switch to dynamic.

New templates to default to dynamic (in sql & coder)

Default set in:

• SQL

  coder/coderd/database/dump.sql

  Line 1742 in 8630a4e

  use_classic_parameter_flow boolean DEFAULT true NOT NULL

• Template create:

  coder/coderd/templates.go

  Line 201 in 8630a4e

  useClassicParameterFlow := ptr.NilToDefault(createTemplate.UseClassicParameterFlow, true)

  (edited)
• Template versions:

  coder/coderd/templateversions.go

  Line 1474 in 8630a4e

  var dynamicTemplate bool

  (edited)