Merge branch 'renovate/go-1.x' into 'master'

Update dependency go to v1.23.1

See merge request !38

go.mod

@@ -2,7 +2,7 @@ module git.autistici.org/ai3/tools/reports-collector
 
 go 1.21
 
-toolchain go1.22.4
+toolchain go1.23.1
 
 require (
 	github.com/chrj/smtpd v0.3.1