fix(deps): bump json 2.20.0→2.21.2 (CVE-2026-71847)

Fixes use-after-free crash in JSON::ResumableParser#partial_value on
truncated duplicate-key streams.

https://claude.ai/code/session_01CDVXuEGetaSKyDrq7p6yrk

Author: claude

runtimes/ruby/Gemfile.lock

@@ -18,7 +18,7 @@ GEM
     cgi (0.5.2)
     connection_pool (3.0.2)
     diff-lcs (1.6.2)
-    json (2.20.0)
+    json (2.21.2)
     language_server-protocol (3.17.0.6)
     lint_roller (1.1.0)
     parallel (1.28.0)
@@ -83,7 +83,7 @@ CHECKSUMS
   cgi (0.5.2) sha256=61ca30298171190fd4fa0d8018e57ada456eae9b7a2b78526debf7f0a0e6f8bb
   connection_pool (3.0.2) sha256=33fff5ba71a12d2aa26cb72b1db8bba2a1a01823559fb01d29eb74c286e62e0a
   diff-lcs (1.6.2) sha256=9ae0d2cba7d4df3075fe8cd8602a8604993efc0dfa934cff568969efb1909962
-  json (2.20.0) sha256=9362bc6e55a952b056abf9167cf053358181c904cb70cd6eee0808ea830fc32b
+  json (2.21.2) sha256=1f1d3b7cf2b3ba1a69beca0bb6db13d5438b80bff3cd54cdaaa620b9b07c1c6a
   language_server-protocol (3.17.0.6) sha256=5ef2c0c138f8267e1bc631d3328347d354f96724b0af22f2c79516120443b7f0
   lint_roller (1.1.0) sha256=2c0c845b632a7d172cb849cc90c1bce937a28c5c8ccccb50dfd46a485003cc87
   parallel (1.28.0) sha256=33e6de1484baf2524792d178b0913fc8eb94c628d6cfe45599ad4458c638c970