Update tool dependencies and fix new lint issues (#36702)

## Summary
- Update golangci-lint v2.9.0 → v2.10.1, misspell v0.7.0 → v0.8.0,
actionlint v1.7.10 → v1.7.11
- Fix 20 new QF1012 staticcheck findings by using `fmt.Fprintf` instead
of `WriteString(fmt.Sprintf(...))`
- Fix SA1019: replace deprecated `ecdsa.PublicKey` field access with
`PublicKey.Bytes()` for JWK encoding, with SEC 1 validation and curve
derived from signing algorithm
- Add unit test for `ToJWK()` covering P-256, P-384, and P-521 curves,
also verifying correct coordinate padding per RFC 7518
- Remove dead staticcheck linter exclusion for "argument x is
overwritten before first use"

## Test plan
- [x] `make lint-go` passes with 0 issues
- [x] `go test ./services/oauth2_provider/ -run
TestECDSASigningKeyToJWK` passes for all curves

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

services/webhook/matrix.go

@@ -174,11 +174,11 @@ func (m matrixConvertor) Push(p *api.PushPayload) (MatrixPayload, error) {
 	repoLink := htmlLinkFormatter(p.Repo.HTMLURL, p.Repo.FullName)
 	branchLink := MatrixLinkToRef(p.Repo.HTMLURL, p.Ref)
 	var text strings.Builder
-	text.WriteString(fmt.Sprintf("[%s] %s pushed %s to %s:<br>", repoLink, p.Pusher.UserName, commitDesc, branchLink))
+	fmt.Fprintf(&text, "[%s] %s pushed %s to %s:<br>", repoLink, p.Pusher.UserName, commitDesc, branchLink)
 
 	// for each commit, generate a new line text
 	for i, commit := range p.Commits {
-		text.WriteString(fmt.Sprintf("%s: %s - %s", htmlLinkFormatter(commit.URL, commit.ID[:7]), commit.Message, commit.Author.Name))
+		fmt.Fprintf(&text, "%s: %s - %s", htmlLinkFormatter(commit.URL, commit.ID[:7]), commit.Message, commit.Author.Name)
 		// add linebreak to each commit but the last
 		if i < len(p.Commits)-1 {
 			text.WriteString("<br>")