Ruby 2.5 Removal

Per our standard Ruby support policy, I am planning to remove Ruby 2.5
from the ports tree, as it will be completely unsupported before the
release of OpenBSD 6.9. Nothing currently depends on it, so
this should cause no problems.

Here's the diff for ruby.port.mk. I also have diffs prepared for
ruby-module.5 and quirks.

Thanks,
Jeremy

Index: ruby.port.mk
===================================================================
RCS file: /cvs/ports/lang/ruby/ruby.port.mk,v
retrieving revision 1.100
diff -u -p -r1.100 ruby.port.mk
--- ruby.port.mk 20 Mar 2020 16:44:24 -0000 1.100
+++ ruby.port.mk 2 Oct 2020 23:09:55 -0000
@@ -24,7 +24,7 @@ MODRUBY_HANDLE_FLAVORS ?= No
# If ruby.pork.mk should handle FLAVORs, define a separate FLAVOR
# for each ruby interpreter
. if !defined(FLAVORS)
-FLAVORS= ruby25 ruby26 ruby27
+FLAVORS= ruby26 ruby27
. if !${CONFIGURE_STYLE:L:Mext}
FLAVORS+= jruby
. endif
@@ -52,11 +52,10 @@ FLAVOR = ruby26

# Check for conflicting FLAVORs and set MODRUBY_REV appropriately based
# on the FLAVOR.
-. for i in ruby25 ruby26 ruby27 jruby
+. for i in ruby26 ruby27 jruby
. if ${FLAVOR:M$i}
MODRUBY_REV = ${i:C/ruby([0-9])/\1./}
-. if ${FLAVOR:N$i:Mruby25} || \
- ${FLAVOR:N$i:Mruby26} || \
+. if ${FLAVOR:N$i:Mruby26} || \
${FLAVOR:N$i:Mruby27} || \
${FLAVOR:N$i:Mjruby}
ERRORS += "Fatal: Conflicting flavors used: ${FLAVOR}"