The Datadog agent was rewritten in Go from version 6. This means
the codebase resides in a new GitHub repository. This change
updates the Nomad telemetry configuration documentation to point
to the latest repo.

docs: update preemption page

This page has not been updated (yet) to reflect that support for all 3 job types (service, batch, system) which shipped in 0.9.2.

The current page implies that preemption is only available for system jobs.

This is early preparation for Nomad 0.12, where we plan to move Preemption from Enterprise feature suite to OSS for all.

website: Adjust the website alert to point to the blog post

core: fix comment on system stack

* documents the scaling block in the JSON Job docs

resolves #7656

* add task-specific restart to JSON Job docs

companion to #7603

* [docs] improved and corrected scaling docs

* Update website/pages/api-docs/json-jobs.mdx
Co-Authored-By: Michael Schurter <mschurter@hashicorp.com>
Co-authored-by: Michael Schurter <mschurter@hashicorp.com>

* update `restart` documentation

#7288 added support for task-specific `restart` policy. this PR updates the docs to reflect that.

* added an explicit example of task-specific restart policy

* Update website/pages/docs/job-specification/restart.mdx

Run task shutdown_delay regardless of service registration

Follow-up for a method missed in the refactor for #7688. The
`volAndPluginLookup` method is only ever called from the server's `CSI`
RPC and never the `ClientCSI` RPC, so move it into that scope.

* pin CSI plugin versions
* ensure failing CSI tests clean up
* allow NOMAD_SHA env var to override makefile

api: testify v1.5.1

Signed-off-by: Yoan Blanc <yoan@dosimple.ch>

The current design of `ClientCSI` RPC requires that callers in the
server know about the free-standing `nodeForControllerPlugin`
function. This makes it difficult to send `ClientCSI` RPC messages
from subpackages of `nomad` and adds a bunch of boilerplate to every
server-side caller of a controller RPC.

This changeset makes it so that the `ClientCSI` RPCs will populate and
validate the controller's client node ID if it hasn't been passed by
the caller, centralizing the logic of picking and validating
controller targets into the `nomad.ClientCSI` struct.

connect: enable configuring sidecar_task.name

connect: correctly handle missing sidecar_service task stanza

task shutdown_delay will currently only run if there are registered
services for the task. This implementation detail isn't explicity stated
anywhere and is defined outside of the service stanza.

This change moves shutdown_delay to be evaluated after prekill hooks are
run, outside of any task runner hooks.

just use time.sleep

Before, the submitted jobspec for sidecar_task would pass
through 2 key validation steps - once for the subset specific
to connect sidecar task definitions, and once again for the set
of normal task definition where the task would actually get
unmarshalled.

The valid keys for the normal task definition did not include
"name", which is supposed to be configurable for the sidecar
task. To fix this, just eliminate the double validation step,
and instead pass-in the correct set of keys to validate against
to the one generic task parser.

Fixes #7680

Before, if the sidecar_service stanza of a connect enabled service
was missing, the job submission would cause a panic in the nomad
agent. Since the panic was happening in the API handler the agent
itself continued running, but this change will the condition more
gracefully.

By fixing the `Copy` method, the API handler now returns the proper
error.

$ nomad job run foo.nomad
Error submitting job: Unexpected response code: 500 (1 error occurred:
	* Task group api validation failed: 2 errors occurred:
	* Missing tasks for task group
	* Task group service validation failed: 1 error occurred:
	* Service[0] count-api validation failed: 1 error occurred:
	* Consul Connect must be native or use a sidecar service

This makes me do a double take every time I run into it, so what if we
just changed it?

Upgrade all golang.org/x packages

docs: fix link to envoy proxy documentation on consul site

Upgrade all golang.org/x packages to pick up fixes and improvements.
Some packages date back to 2018 and so much improvement happened since
then!

Prepare for 0.11.1 release

vendor: upgrade golang.org/x/net packages

changelog: add 0.11.0 release date.

golang.org/net packages are ancient - upgrading them to pick up
important fixes, e.g. https://go-review.googlesource.com/c/go/+/87298/

e2e: add a convenient creation script

Add a convenience Makefile for creating e2e environment for manual
debugging.

dev: Use go mod for managing hashicorp/go-msgpack