ruby-ng.eclass: optimize: use pattern for old ruby impls

Not much improvement on a grand scale, but for dev-ruby/sinatra at least, we get:
```
$ pk pkg source $(pkg) --repo ~/g/ --bench 5s # before
dev-ruby/sinatra-3.0.5::/home/sam/g/: mean: 76.25ms, min: 59.23ms, max: 83.674ms, σ = 4.247ms, N = 66
dev-ruby/sinatra-3.0.5-r1::/home/sam/g/: mean: 77.465ms, min: 61.782ms, max: 85.127ms, σ = 3.592ms, N = 65
dev-ruby/sinatra-3.0.6::/home/sam/g/: mean: 80.192ms, min: 60.922ms, max: 84.951ms, σ = 3.899ms, N = 63
dev-ruby/sinatra-2.2.3::/home/sam/g/: mean: 80.389ms, min: 56.818ms, max: 86.915ms, σ = 4.508ms, N = 63

$ pk pkg source $(pkg) --repo ~/g/ --bench 5s # after
dev-ruby/sinatra-3.0.6::/home/sam/g/: mean: 72.761ms, min: 58.627ms, max: 76.161ms, σ = 3.276ms, N = 69
dev-ruby/sinatra-3.0.5-r1::/home/sam/g/: mean: 72.967ms, min: 60.127ms, max: 76.75ms, σ = 3.176ms, N = 69
dev-ruby/sinatra-3.0.5::/home/sam/g/: mean: 69.004ms, min: 58.344ms, max: 73.661ms, σ = 3.3ms, N = 73
dev-ruby/sinatra-2.2.3::/home/sam/g/: mean: 71.061ms, min: 55.144ms, max: 74.563ms, σ = 3.848ms, N = 71
```

A tiny, but seemingly consistent improvement.

Thanks to mgorny for the idea.

Bug: https://bugs.gentoo.org/908465
Signed-off-by: Sam James <sam@gentoo.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/eclass/ruby-ng.eclass b/eclass/ruby-ng.eclass
index 8befa086ef02..5a6edb1bf608 100644
--- a/eclass/ruby-ng.eclass
+++ b/eclass/ruby-ng.eclass
@@ -107,7 +107,7 @@ _ruby_get_all_impls() {
 	for i in ${USE_RUBY}; do
 		case ${i} in
 			# removed implementations
-			ruby19|ruby20|ruby21|ruby22|ruby23|ruby24|ruby25|ruby26|ruby27|jruby)
+			ruby19|ruby2[0-7]|jruby)
 				;;
 			*)
 				found_valid_impl=1