Clear Rails' default backtrace filters from Sentry's backtrace cleaner

In Rails 7.2, Rails's backtrace cleaner, which sentry-rails' backtrace
cleaner inherits from, starts shortening gem's paths in backtraces. This
will prevent sentry-ruby's `Sentry::Backtrace` from handling them correctly,
which will result in issues like #2472.

This commit avoids the issue by clearing the default filters that
Sentry's backtrace cleaner inherits.

sentry-rails/lib/sentry/rails/backtrace_cleaner.rb

@@ -11,8 +11,10 @@ class BacktraceCleaner < ActiveSupport::BacktraceCleaner
 
       def initialize
         super
-        # we don't want any default silencers because they're too aggressive
+        # We don't want any default silencers because they're too aggressive
         remove_silencers!
+        # We don't want any default filters because Rails 7.2 starts shortening the paths. See #2472
+        remove_filters!
 
         @root = "#{Sentry.configuration.project_root}/"
         add_filter do |line|

sentry-rails/spec/sentry/rails_spec.rb

@@ -242,6 +242,16 @@ def capture_in_separate_process(exit_code:)
       expect(traces.dig(-1, "function")).to be_nil
     end
 
+    it "makes sure BacktraceCleaner gem cleanup doesn't affect context lines population" do
+      get "/view_exception"
+
+      traces = event.dig("exception", "values", 0, "stacktrace", "frames")
+      gem_frame = traces.find { |t| t["abs_path"].match(/actionview/) }
+      expect(gem_frame["pre_context"]).not_to be_empty
+      expect(gem_frame["post_context"]).not_to be_empty
+      expect(gem_frame["context_line"]).not_to be_empty
+    end
+
     it "doesn't filters exception backtrace if backtrace_cleanup_callback is overridden" do
       make_basic_app do |config|
         config.backtrace_cleanup_callback = lambda { |backtrace| backtrace }