Inconsistent + obsolete golang versions

[mmontour1306]

Issue Type

[ X ] bug report
[ ] feature request

Current Behavior

Our build system is using golang versions which are not consistent across the monorepo, and including older versions which are no longer supported.

$ grep -I --recursive "FROM golang" .
./ops/docker/Dockerfile.geth:FROM golang:1.15-alpine3.13 as builder ./ops/docker/Dockerfile.op_exporter:FROM golang:1.16 as builder ./ops/docker/Dockerfile.gas-oracle:FROM golang:1.15-alpine3.13 as builder ./ops/docker/Dockerfile.batch-submitter:FROM golang:1.17.3-alpine3.13 as builder ./go/proxyd/Dockerfile:FROM golang:1.18.0-alpine3.15 as builder

See https://go.dev/doc/devel/release - the current major release is 1.19 and therefore anything prior to 1.18 is no longer considered to be supported.

Expected Behavior

We should consistently build and test with one supported version of the golang compiler.