chore(deps): update chroma, regexp2 v2, replace dimiro1/reply (#37858)

- Update `github.com/alecthomas/chroma/v2` to `v2.25.0`.
- Migrate `github.com/dlclark/regexp2` to `/v2` (incorporates
https://github.com/go-gitea/gitea/pull/37664); drop the renovate pin.
- Replace the unmaintained `github.com/dimiro1/reply` (the last consumer
of `regexp2` v1 in our own code) with a small built-in reply parser for
incoming mail.

Signed-off-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>
Co-authored-by: Nicolas <bircni@icloud.com>

go.mod

@@ -23,7 +23,7 @@ require (
 	github.com/ProtonMail/go-crypto v1.4.1
 	github.com/PuerkitoBio/goquery v1.12.0
 	github.com/SaveTheRbtz/zstd-seekable-format-go/pkg v0.8.3
-	github.com/alecthomas/chroma/v2 v2.24.1
+	github.com/alecthomas/chroma/v2 v2.25.0
 	github.com/aws/aws-sdk-go-v2/credentials v1.19.16
 	github.com/aws/aws-sdk-go-v2/service/codecommit v1.33.14
 	github.com/blakesmith/ar v0.0.0-20190502131153-809d4375e1fb
@@ -33,8 +33,7 @@ require (
 	github.com/caddyserver/certmagic v0.25.3
 	github.com/charmbracelet/git-lfs-transfer v0.1.1-0.20260309112543-12416315a635
 	github.com/chi-middleware/proxy v1.1.1
-	github.com/dimiro1/reply v0.0.0-20200315094148-d0136a4c9e21
-	github.com/dlclark/regexp2 v1.12.0
+	github.com/dlclark/regexp2/v2 v2.1.0
 	github.com/dsnet/compress v0.0.2-0.20230904184137-39efe44ab707
 	github.com/dustin/go-humanize v1.0.1
 	github.com/editorconfig/editorconfig-core-go/v2 v2.6.4
@@ -178,6 +177,7 @@ require (
 	github.com/cyphar/filepath-securejoin v0.6.1 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/davidmz/go-pageant v1.0.2 // indirect
+	github.com/dlclark/regexp2 v1.12.0 // indirect
 	github.com/emersion/go-sasl v0.0.0-20241020182733-b788ff22d5a6 // indirect
 	github.com/fatih/color v1.19.0 // indirect
 	github.com/fxamacker/cbor/v2 v2.9.2 // indirect