Address Ruby 3.4 frozen string warnings and improve flaky tests

Author: rosa

test/integration/processes_lifecycle_test.rb

@@ -121,7 +121,9 @@ class ProcessesLifecycleTest < ActiveSupport::TestCase
     no_pause = enqueue_store_result_job("no pause")
     pause = enqueue_store_result_job("pause", pause: SolidQueue.shutdown_timeout + 10.second)
 
-    signal_process(@pid, :TERM, wait: 0.5.second)
+    wait_while_with_timeout(1.second) { SolidQueue::ReadyExecution.count > 0 }
+
+    signal_process(@pid, :TERM, wait: 0.5)
 
     sleep(SolidQueue.shutdown_timeout + 0.5.second)
 
@@ -204,6 +206,7 @@ class ProcessesLifecycleTest < ActiveSupport::TestCase
 
     worker = find_processes_registered_as("Worker").first
 
+    wait_while_with_timeout(1.second) { SolidQueue::ReadyExecution.count > 0 }
     signal_process(worker.pid, :TERM, wait: 0.1.second)
 
     # Worker is gone

test/models/solid_queue/process_test.rb

@@ -60,7 +60,7 @@ class SolidQueue::ProcessTest < ActiveSupport::TestCase
     worker = SolidQueue::Worker.new(queues: "*", threads: 3, polling_interval: 0.2)
     hostname = "Basecamp’s-Computer"
 
-    Socket.stub :gethostname, hostname.force_encoding("ASCII-8BIT") do
+    Socket.stub :gethostname, hostname.dup.force_encoding("ASCII-8BIT") do
       worker.start
       wait_for_registered_processes(1, timeout: 1.second)