chore(BRIDGE-574): bump go toolchain

Author: annatar

.github/actions/govulncheck.sh

@@ -8,8 +8,6 @@ main(){
 
     jq -r '.finding | select( (.osv != null) and (.trace[0].function != null) ) | .osv ' < vulns.json > vulns_osv_ids.txt
 
-    ignore GO-2026-5037 "BRIDGE-565 crypto/x509 fixes quadratic cost of verifying large DNS SAN lists."
-
     has_vulns
 
     echo

go.mod

@@ -2,7 +2,7 @@ module github.com/ProtonMail/gluon
 
 go 1.26.1
 
-toolchain go1.26.3
+toolchain go1.26.4
 
 require (
 	github.com/ProtonMail/go-mbox v1.1.0