Finish Removing golint (#1746)

* Set GO111MODULE to auto in golint script– #1743

As mentioned in #1743 the Go modules environment flag is set to `off`
in the script which appears to cause a warning message for each module
of the codebase that it is "not in GOROOT".

Set to `auto` as this allows the same build to be run the original way
should someone choose to delete the `go.mod` file from the project root.

* Remove redundant code – golint script

Go 1.17 ignores `GO111MODULE` and there are no directories in the
project root called `mock`.

* Replace `golint` with `go vet`

`golint` is deprecated (and frozen) replace with the current `go vet`.
This reported one issue on `main` branch:
```pkg/stash/with_etcd.go:33:28:
loop variable ep captured by func literal```

Fixed loop variable capture with extraction to parameterised anonymous
function passed loop variable and passed in to `errgroup.Go` call.

* Finish Removing `golint`

Removed remaining references to `golint` in dev doc, Makefile,
bash scripts, and powershell build scripts.
Removed `get_dev_tools.sh` and `get_dev_tools.ps1` as they only install
the removed `golint` package.

scripts/ps/check_govet.ps1

@@ -1,7 +1,7 @@
-# check_golint.ps1
+# check_govet.ps1
 # Run the linter on everything
 
-$out = & golint -set_exit_status $(& go list ./...)
+$out = & go vet ./...
 if ($LastExitCode -ne 0) {
     Write-Error $out
 }

scripts/ps/get_dev_tools.ps1

@@ -1,4 +0,0 @@
-# install_dev_deps.ps1
-# Ensure that the tools needed to build locally are present
-
-& go get github.com/golang/lint/golint