Use the development versions of minitest and debug gems

This is a preparation for a new message format of NameError.
[Feature #18285]

https://github.com/minitest/minitest/pull/942
https://github.com/ruby/debug/pull/889

gems/bundled_gems

@@ -5,7 +5,7 @@
 # - repository-url: URL from where clone for test
 # - revision: revision in repository-url to test
 #   if `revision` is not given, "v"+`version` or `version` will be used.
-minitest        5.17.0  https://github.com/seattlerb/minitest
+minitest        5.17.0  https://github.com/seattlerb/minitest d4fc359899f96944be147609e045b9e921881f19
 power_assert    2.0.3   https://github.com/ruby/power_assert
 rake            13.0.6  https://github.com/ruby/rake
 test-unit       3.5.7   https://github.com/test-unit/test-unit
@@ -19,4 +19,4 @@ matrix          0.4.2   https://github.com/ruby/matrix
 prime           0.1.2   https://github.com/ruby/prime
 rbs             2.8.4   https://github.com/ruby/rbs
 typeprof        0.21.4  https://github.com/ruby/typeprof
-debug           1.7.1   https://github.com/ruby/debug
+debug           1.7.1   https://github.com/ruby/debug d7bf3b2e4502eb0f07a67f00e5fce5a0d661189e