Update supported Go versions

Now that 1.23 is out, update the supported version matrix to Go 1.21
through 1.23. This allows us to start using `log/slog`.
* Update generated tests.

Signed-off-by: SuperQ <superq@gmail.com>

.github/workflows/go.yml

@@ -54,7 +54,7 @@ jobs:
 
       - name: Run style and unused
         uses: dagger/dagger-for-github@v6
-        if: ${{ matrix.go_version == '1.20' }}
+        if: ${{ matrix.go_version == '1.21' }}
         with:
           version: "latest"
           verb: call

.github/workflows/golangci-lint.yml

@@ -28,7 +28,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@0a12ed9d6a96ab950c8f026ed9f722fe0da7ef32 # v5.0.2
         with:
-          go-version: 1.22.x
+          go-version: 1.23.x
       - name: Install snmp_exporter/generator dependencies
         run: sudo apt-get update && sudo apt-get -y install libsnmp-dev
         if: github.repository == 'prometheus/snmp_exporter'

README.md

@@ -10,8 +10,8 @@ This is the [Go](http://golang.org) client library for
 instrumenting application code, and one for creating clients that talk to the
 Prometheus HTTP API.
 
-**This library requires Go1.20 or later.**
-> The library mandates the use of Go1.20 or subsequent versions. While it has demonstrated functionality with versions as old as Go 1.17, our commitment remains to offer support and rectifications for only the most recent three major releases.
+**This library requires Go1.21 or later.**
+> The library mandates the use of Go1.21 or subsequent versions. While it has demonstrated functionality with versions as old as Go 1.17, our commitment remains to offer support and rectifications for only the most recent three major releases.
 
 ## Important note about releases and stability
 

go.mod

@@ -1,6 +1,6 @@
 module github.com/prometheus/client_golang
 
-go 1.20
+go 1.21
 
 require (
 	github.com/beorn7/perks v1.0.1

go.sum

@@ -41,9 +41,11 @@ github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0leargg
 github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
+github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
 golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
 golang.org/x/oauth2 v0.21.0 h1:tsimM75w1tF/uws5rbeHzIWxEqElMehnc+iW793zsZs=
@@ -56,6 +58,8 @@ google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6h
 google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=