Fix haml lint Rubocop `Style/RedundantStringCoercion` cop (#25975)

.haml-lint_todo.yml

 # This configuration was generated by
 # `haml-lint --auto-gen-config`
-# on 2023-07-11 23:58:05 +0200 using Haml-Lint version 0.48.0.
+# on 2023-07-13 11:24:52 -0400 using Haml-Lint version 0.48.0.
 # The point is for the user to remove these configuration records
 # one by one as the lints are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of Haml-Lint, may require this file to be generated again.
 
 linters:
-  # Offense count: 94
+  # Offense count: 93
   RuboCop:
     enabled: false
 

app/views/settings/imports/show.html.haml

 - content_for :page_title do
-  = t("imports.titles.#{@bulk_import.type.to_s}")
+  = t("imports.titles.#{@bulk_import.type}")
 
 - if @bulk_import.likely_mismatched?
   .flash-message.warning= t("imports.mismatched_types_warning")
 
 - if @bulk_import.overwrite?
-  %p.hint= t("imports.overwrite_preambles.#{@bulk_import.type.to_s}_html", filename: @bulk_import.original_filename, total_items: @bulk_import.total_items)
+  %p.hint= t("imports.overwrite_preambles.#{@bulk_import.type}_html", filename: @bulk_import.original_filename, total_items: @bulk_import.total_items)
 - else
-  %p.hint= t("imports.preambles.#{@bulk_import.type.to_s}_html", filename: @bulk_import.original_filename, total_items: @bulk_import.total_items)
+  %p.hint= t("imports.preambles.#{@bulk_import.type}_html", filename: @bulk_import.original_filename, total_items: @bulk_import.total_items)
 
 .simple_form
   .actions