maint(go): update to go1.23 (#222)

go1.20 is ollllld. get us onto something that receives updates/support
from golang team.

.circleci/config.yml

@@ -3,7 +3,7 @@ version: 2.1
 executors:
   linuxgo:
     docker:
-      - image: cimg/go:1.20
+      - image: cimg/go:1.23
 
 commands:
   go-build:

go.mod

@@ -1,6 +1,8 @@
 module github.com/honeycombio/buildevents
 
-go 1.15
+go 1.23.0
+
+toolchain go1.23.2
 
 require (
 	github.com/honeycombio/beeline-go v1.17.0
@@ -11,4 +13,19 @@ require (
 	github.com/stretchr/testify v1.9.0
 )
 
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a // indirect
+	github.com/facebookgo/limitgroup v0.0.0-20150612190941-6abd8d71ec01 // indirect
+	github.com/facebookgo/muster v0.0.0-20150708232844-fd3d7953fd52 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/klauspost/compress v1.17.8 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/vmihailenco/msgpack/v5 v5.4.1 // indirect
+	github.com/vmihailenco/tagparser/v2 v2.0.0 // indirect
+	gopkg.in/alexcesaro/statsd.v2 v2.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
+
 replace github.com/jszwedko/go-circleci => github.com/maplebed/go-circleci v0.0.0-20191121000249-089ef54587e5