Bump github.com/stretchr/testify from 1.11.1 to 1.12.0 (#6641)

Bumps [github.com/stretchr/testify](https://github.com/stretchr/testify) from 1.11.1 to 1.12.0.
- [Release notes](https://github.com/stretchr/testify/releases)
- [Commits](https://github.com/stretchr/testify/compare/v1.11.1...v1.12.0)

---
updated-dependencies:
- dependency-name: github.com/stretchr/testify
  dependency-version: 1.12.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

go.mod

@@ -19,7 +19,7 @@ require (
 	github.com/robfig/cron/v3 v3.0.1
 	github.com/sagernet/sing v0.5.1
 	github.com/sagernet/sing-shadowsocks v0.2.7
-	github.com/stretchr/testify v1.11.1
+	github.com/stretchr/testify v1.12.0
 	github.com/vishvananda/netlink v1.3.1
 	github.com/xtls/reality v0.0.0-20260322125925-9234c772ba8f
 	go4.org/netipx v0.0.0-20231129151722-fdeea329fbba
@@ -40,7 +40,6 @@ require (
 
 require (
 	github.com/andybalholm/brotli v1.0.6 // indirect
-	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/google/btree v1.1.2 // indirect
 	github.com/juju/ratelimit v1.0.2 // indirect
 	github.com/klauspost/compress v1.17.4 // indirect
@@ -48,7 +47,6 @@ require (
 	github.com/pion/dtls/v3 v3.1.4 // indirect
 	github.com/pion/logging v0.2.4 // indirect
 	github.com/pion/transport/v4 v4.0.2 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/quic-go/qpack v0.6.0 // indirect
 	github.com/vishvananda/netns v0.0.5 // indirect
 	github.com/wlynxg/anet v0.0.5 // indirect