fix(deps): update module github.com/lestrrat-go/jwx/v3 to v4

Migrate to jwx v4 per MIGRATION.md:
- jwk.Import now generic; use jwk.Import[jwk.Key](raw)
- Set GOEXPERIMENT=jsonv2 (v4 uses encoding/json/v2)

.version

@@ -1,3 +1,3 @@
 {
-  "version": "0.7.3"
+  "version": "0.7.2"
 }

CHANGELOG.md

@@ -2,38 +2,6 @@
 
 All notable changes to this project will be documented in this file.
 
-## [0.7.3] - 2026-04-22
-
-### 🐛 Bug Fixes
-
-- *(deps)* Update module github.com/alecthomas/kong to v1.15.0 (#285)
-- *(deps)* Update module github.com/lestrrat-go/jwx/v3 to v3.1.0 (#296)
-- *(deps)* Update module github.com/lestrrat-go/jwx/v3 to v4 (#297)
-
-### ⚙️ Miscellaneous Tasks
-
-- *(deps)* Update gcr.io/distroless/static-debian12 docker digest to 20bc6c0 (#262)
-- *(deps)* Update golang:1.26 docker digest to b39810f (#264)
-- *(deps)* Update golang:1.26 docker digest to b751797 (#265)
-- *(deps)* Update golang:1.26 docker digest to a9c4aac (#267)
-- *(deps)* Update golang:1.26 docker digest to 9edf713 (#269)
-- *(deps)* Update golang:1.26 docker digest to fb612b7 (#270)
-- *(deps)* Update golang:1.26 docker digest to e2ddb15 (#271)
-- *(deps)* Update golang:1.26 docker digest to cdebbd5 (#272)
-- *(deps)* Update golang:1.26 docker digest to c7e98cc (#274)
-- *(deps)* Update golang:1.26 docker digest to 318ba17 (#276)
-- *(deps)* Update golang:1.26 docker digest to 16e774b (#277)
-- *(deps)* Update golang:1.26 docker digest to dd25c49 (#279)
-- *(deps)* Update golang:1.26 docker digest to c42e4d7 (#281)
-- *(deps)* Update golang:1.26 docker digest to 595c784 (#283)
-- *(deps)* Update golang:1.26 docker digest to 42ebbf7 (#286)
-- *(deps)* Update golang:1.26 docker digest to 5e69504 (#287)
-- *(deps)* Update golang:1.26 docker digest to cd78d88 (#289)
-- *(deps)* Update golang:1.26 docker digest to ec4debb (#291)
-- *(deps)* Update golang:1.26 docker digest to fcdb3e4 (#293)
-- *(deps)* Update golang:1.26 docker digest to 5f3787b (#295)
-- *(deps)* Update golang:1.26 docker digest to 46d487a (#299)
-
 ## [0.7.2] - 2026-02-12
 
 ### 🐛 Bug Fixes