When upgrading to Drupal 9 it can be handy to look up the uninstalled modules first, to remove them.

Use this command:

drush pm:list --type=Module --status="disabled,not installed" --no-core 

This resulted for me in this list:

  --------------------------------- ------------------------------------------------------------------------ ---------- ----------------
  Package                           Name                                                                     Status     Version
 --------------------------------- ------------------------------------------------------------------------ ---------- ----------------
  Spam control                      CAPTCHA (captcha)                                                        Disabled   8.x-1.2
  Spam control                      Image CAPTCHA (image_captcha)                                            Disabled   8.x-1.2
  Testing                           captcha long form id test module (captcha_long_form_id_test)             Disabled   8.x-1.2
  Testing                           Captcha Test (captcha_test)                                              Disabled   8.x-1.2
  Chaos tool suite (Experimental)   Chaos Tools Blocks (ctools_block)                                        Disabled   8.x-3.7
  Other                             Entity Mask (ctools_entity_mask)                                         Disabled   8.x-3.7
  Chaos tool suite (Experimental)   Chaos Tools Views (ctools_views)                                         Disabled   8.x-3.7
  Web services                      Default content (default_content)                                        Disabled   8.x-1.0-alpha9
  Media                             Entity Browser IEF (entity_browser_entity_form)                          Disabled   8.x-2.6
  Media                             Entity Browser example (entity_browser_example)                          Disabled   8.x-2.6
  Search                            Facets Range Widget (facets_range_widget)                                Disabled   8.x-1.8
  Search                            Facets summary (Experimental) (facets_summary)                           Disabled   8.x-1.8
  Migration                         Field Group Migrate (field_group_migrate)                                Disabled   8.x-3.1
  Field types                       Formatter field (formatter_field)                                        Disabled   8.x-1.1
  Paragraphs                        Paragraphs Demo (paragraphs_demo)                                        Disabled   8.x-1.12
  Paragraphs                        Paragraphs Library (paragraphs_library)                                  Disabled   8.x-1.12
  Paragraphs                        Paragraphs Type Permissions (paragraphs_type_permissions)                Disabled   8.x-1.12
  Spam control                      reCAPTCHA (recaptcha)                                                    Disabled   8.x-2.5
  Other                             Redirect Domain (redirect_domain)                                        Disabled   8.x-1.6
  Search                            Database Search Defaults (search_api_db_defaults)                        Disabled   8.x-1.19
  Search                            Search API Sort Priority: Solr Support (search_api_sort_priority_solr)   Disabled   8.x-1.9
  SEO                               Simple XML Sitemap (Search engines) (simple_sitemap_engines)             Disabled   8.x-3.10
  SEO                               Simple XML Sitemap (Views) (simple_sitemap_views)                        Disabled   8.x-3.10
  Social media                      Social share (social_share)                                              Disabled   8.x-2.0-beta6
  Other                             Typed Data (typed_data)                                                  Disabled   8.x-1.0-alpha5
  Video Embed Field                 Video Embed Media - Migrate to core oEmbed (vem_migrate_oembed)          Disabled   8.x-2.4
  Video Embed Field                 Video Embed Media (video_embed_media)                                    Disabled   8.x-2.4
  Video Embed Field                 Video Embed WYSIWYG (video_embed_wysiwyg)                                Disabled   8.x-2.4
  Video Embed Field                 Video Embed Field (video_embed_field)                                    Disabled   8.x-2.4
  Views Bulk Operations             Actions Permissions (actions_permissions)                                Disabled   8.x-3.13
  Examples                          Views Bulk Operations example (views_bulk_operations_example)            Disabled   8.x-3.13


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