fix: translate elixir :warn log level to :warning

Elixir 1.15 hard-depcreates Logger.warn.  Custom logger backends that
still use the legacy custom backend API must translate the log level to
avoid emitting a deprecation warning.

Author: dustinfarris

lib/sentry/logger_backend.ex

@@ -70,6 +70,8 @@ defmodule Sentry.LoggerBackend do
   end
 
   def handle_event({level, _gl, {Logger, msg, _ts, meta}}, state) do
+    level = maybe_ensure_warning_level(level)
+
     if Logger.compare_levels(level, state.level) != :lt and
          not excluded_domain?(meta[:domain], state) do
       log(level, msg, meta, state)
@@ -189,4 +191,14 @@ defmodule Sentry.LoggerBackend do
         "debug"
     end
   end
+
+  defp maybe_ensure_warning_level(:warn) do
+    if Version.compare(System.version, "1.11.0") == :lt do
+      :warn
+    else
+      :warning
+    end
+  end
+
+  defp maybe_ensure_warning_level(level), do: level
 end

test/logger_backend_test.exs

@@ -421,7 +421,7 @@ defmodule Sentry.LoggerBackendTest do
 
     capture_log(fn ->
       Sentry.Context.set_user_context(%{user_id: 3})
-      Logger.warn("testing")
+      Logger.warning("testing")
       assert_receive("API called")
     end)
   after
@@ -566,7 +566,7 @@ defmodule Sentry.LoggerBackendTest do
     end)
 
     capture_log(fn ->
-      Logger.warn("warn")
+      Logger.warning("warn")
 
       assert_receive("API called")
     end)