Build with Go 1.20, upgrade some deps

Dockerfile

-FROM golang:1.18 as build
+FROM docker.io/library/golang:1.20.1 as build
 ADD . /src
 RUN cd /src && go build -tags netgo -o service-prober ./cmd/service-prober && strip service-prober
 

go.mod

 module git.autistici.org/ai3/tools/service-prober
 
-go 1.15
-
-// temporary replacement until ongoing MR is merged upstream
-replace github.com/ooni/minivpn v0.0.4 => github.com/ainghazal/minivpn v0.0.4-0.20220623143937-59ea5af1507c
+go 1.19
 
 require (
-	bazil.org/fuse v0.0.0-20200407214033-5883e5a4b512 // indirect
 	github.com/PuerkitoBio/goquery v1.8.1
-	github.com/bits-and-blooms/bitset v1.2.0 // indirect
-	github.com/docker/docker v20.10.13+incompatible // indirect
-	github.com/mitchellh/mapstructure v1.4.3 // indirect
-	github.com/moby/term v0.0.0-20210619224110-3f7ff695adc6 // indirect
 	github.com/ooni/minivpn v0.0.5
 	github.com/prometheus/client_golang v1.13.0
-	github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb // indirect
-	golang.zx2c4.com/go118/netip v0.0.0-20211105124833-002a02cb0e53 // indirect
-	gvisor.dev/gvisor v0.0.0-20230816012645-8f0c59c3fa00 // indirect
+)
+
+require (
+	github.com/andybalholm/cascadia v1.3.1 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/btree v1.0.1 // indirect
+	github.com/google/gopacket v1.1.19 // indirect
+	github.com/google/uuid v1.3.0 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/common v0.37.0 // indirect
+	github.com/prometheus/procfs v0.8.0 // indirect
+	github.com/refraction-networking/utls v1.1.0 // indirect
+	golang.org/x/crypto v0.6.0 // indirect
+	golang.org/x/net v0.7.0 // indirect
+	golang.org/x/sync v0.1.0 // indirect
+	golang.org/x/sys v0.5.1-0.20230222185716-a3b23cc77e89 // indirect
+	golang.org/x/time v0.0.0-20191024005414-555d28b269f0 // indirect
+	golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2 // indirect
+	golang.zx2c4.com/wireguard v0.0.0-20230704135630-469159ecf7d1 // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
+	gvisor.dev/gvisor v0.0.0-20221203005347-703fd9b7fbc0 // indirect
 )