Update ecosystem test rack dependency version and gem test pack version

Author: bjfish

test/truffle/ecosystem/blog5/Gemfile.lock

@@ -81,7 +81,7 @@ GEM
       mini_portile2 (~> 2.4.0)
     pg (1.1.4)
     puma (3.12.2)
-    rack (2.0.7)
+    rack (2.0.8)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
     rails (5.2.3)

test/truffle/ecosystem/blog6/Gemfile.lock

@@ -88,7 +88,7 @@ GEM
       mini_portile2 (~> 2.4.0)
     pg (1.1.3)
     puma (3.12.2)
-    rack (2.0.7)
+    rack (2.0.8)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
     rails (6.0.0)

tool/jt.rb

@@ -30,7 +30,7 @@
 GRAAL_DIR = File.expand_path('../graal', TRUFFLERUBY_DIR)
 PROFILES_DIR = "#{TRUFFLERUBY_DIR}/profiles"
 
-TRUFFLERUBY_GEM_TEST_PACK_VERSION = 'fa8e5817c1496e136caa1f994864712b2faf6bc7'
+TRUFFLERUBY_GEM_TEST_PACK_VERSION = '74d5e0101bb143a4f9a2a60664328ad936b05594'
 
 JDEBUG = '--vm.agentlib:jdwp=transport=dt_socket,server=y,address=8000,suspend=y'
 METRICS_REPS = Integer(ENV['TRUFFLERUBY_METRICS_REPS'] || 10)