Remove Drone config (#579)

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

Makefile

@@ -96,14 +96,3 @@ endif
 
 .tools/bin/protoc-gen-go: .tools
 	GOPATH=$(CURDIR)/.tools go install github.com/golang/protobuf/protoc-gen-go@v1.3.1
-
-.PHONY: drone
-drone: .drone/drone.yml
-
-.drone/drone.yml: .drone/drone.jsonnet
-	# Drone's jsonnet formatting causes issues where arrays disappear
-	drone jsonnet --source $< --target $@.tmp --stream --format=false
-	drone sign --save grafana/dskit $@.tmp
-	drone lint --trusted $@.tmp
-	# When all passes move to correct destination
-	mv $@.tmp $@

contributing/how-to-upgrade-golang-version.md

@@ -1,7 +1,5 @@
 # How to upgrade Golang version
 
-1. `go mod edit -go=1.17`
+1. `go mod edit -go=1.23`
 1. `go mod vendor && go mod tidy`
-1. Change Drone image in `.drone/drone.jsonnet`
-1. Export $DRONE_SERVER and $DRONE_TOKEN environment variables (you can get them logging in to [https://drone.grafana.net](https://drone.grafana.net))
-1. `make .drone/drone.yml`
+1. Change active Go version and supported Go versions in `.github/workflows/test-build.yml`