Allow sidecars, like coprocessors, in the official helm chart.

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**Checklist**

Complete the checklist (and note appropriate exceptions) before a final
PR is raised.

- [x] Changes are compatible[^1]
- [ ] Documentation[^2] completed
- [x] Performance impact assessed and acceptable
- Tests added and passing[^3]
    - [ ] Unit Tests
    - [ ] Integration Tests
    - [ ] Manual Tests

**Exceptions**

*Note any exceptions here*

**Notes**

[^1]. It may be appropriate to bring upcoming changes to the attention
of other (impacted) groups. Please endeavour to do this before seeking
PR approval. The mechanism for doing this will vary considerably, so use
your judgement as to how and when to do this.
[^2]. Configuration is an important part of many changes. Where
applicable please try to document configuration examples.
[^3]. Tick whichever testing boxes are applicable. If you are adding
Manual Tests:
- please document the manual testing (extensively) in the Exceptions.
- please raise a separate issue to automate the test and label it (or
ask for it to be labeled) as `manual test`

Co-authored-by: Gary Pennington <gary@apollographql.com>

Fix #2862, #2861, #2886

### Coprocessor: add fields to the router and the subgraph stage

This changeset adds several (read only) fields to coprocessor stages:

router request:
    - path
    - method

router response:
    - status_code

subgraph response:
    - status_code

It removes the`coprocessor.subgraph.all.response.uri` key (that was
unused), with a migration.

It also fixes a bug where a coprocessor operating at the
`router_request` stage would fail to deserialize an empty body (which
happens for GET requests).

---------

Co-authored-by: Jesse Rosenberger <git@jro.cc>
Co-authored-by: Gary Pennington <gary@apollographql.com>

This PR enables the `vendored-openssl` feature on the `git2` crate in
the `xtask` workspace crate.

Fixes #2904

Add the capability for Helm users to set extra labels attached to the
router deployment and its pods.

Co-authored-by: Gary Pennington <gary@apollographql.com>

This changeset updates thee xtask and router Cargo.lock.

uses cache-control headers from subgraphs to determine an overally
cache-control policy

partially addresses #326