Lower explore page limit

Lowers the limit for explore to 50 pages deep.

app/controllers/explore/projects_controller.rb

@@ -9,13 +9,16 @@ class Explore::ProjectsController < Explore::ApplicationController
   include SortingPreference
 
   MIN_SEARCH_LENGTH = 3
+  PAGE_LIMIT = 50
 
   before_action :set_non_archived_param
   before_action :set_sorting
 
-  # Limit taken from https://gitlab.com/gitlab-org/gitlab/issues/38357
+  # For background information on the limit, see:
+  #   https://gitlab.com/gitlab-org/gitlab/-/issues/38357
+  #   https://gitlab.com/gitlab-org/gitlab/-/issues/262682
   before_action only: [:index, :trending, :starred] do
-    limit_pages(200)
+    limit_pages(PAGE_LIMIT)
   end
 
   rescue_from PageOutOfBoundsError, with: :page_out_of_bounds

changelogs/unreleased/lower-explore-pages.yml

+---
+title: Lower /explore page limit
+merge_request: 50233
+author:
+type: performance

spec/controllers/explore/projects_controller_spec.rb

@@ -60,7 +60,7 @@ RSpec.describe Explore::ProjectsController do
   end
 
   shared_examples "blocks high page numbers" do
-    let(:page_limit) { 200 }
+    let(:page_limit) { described_class::PAGE_LIMIT }
 
     context "page number is too high" do
       [:index, :trending, :starred].each do |endpoint|