ruby: disable rdoc due to non-reproducibility

The issue is reported upstream:
https://bugs.ruby-lang.org/issues/18456

Otherwise I do not feel that further investigation of rdoc's parser to find
out the source of non-determinism is worth the time.

(From OE-Core rev: 208021f7212a8a790c350ccca720695c5bcbb1ca)

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/selftest/cases/reproducible.py

@@ -17,12 +17,9 @@ import stat
 import os
 import datetime
 
-# ruby-ri-docs, meson:
-#https://autobuilder.yocto.io/pub/repro-fail/oe-reproducible-20210215-0_td9la2/packages/diff-html/
 # rust-llvm:
 #https://autobuilder.yocto.io/pub/repro-fail/oe-reproducible-20210825-kaihham6/
 exclude_packages = [
-	'ruby-ri-docs',
 	'rust-llvm-liblto',
 	'rust-llvm-staticdev'
 	]

meta/recipes-devtools/ruby/ruby_3.0.3.bb

@@ -21,6 +21,9 @@ PACKAGECONFIG += "${@bb.utils.filter('DISTRO_FEATURES', 'ipv6', d)}"
 PACKAGECONFIG[valgrind] = "--with-valgrind=yes, --with-valgrind=no, valgrind"
 PACKAGECONFIG[gmp] = "--with-gmp=yes, --with-gmp=no, gmp"
 PACKAGECONFIG[ipv6] = "--enable-ipv6, --disable-ipv6,"
+# rdoc is off by default due to non-reproducibility reported in
+# https://bugs.ruby-lang.org/issues/18456
+PACKAGECONFIG[rdoc] = "--enable-install-rdoc,--disable-install-rdoc,"
 
 EXTRA_OECONF = "\
     --disable-versioned-paths \