Add proxy support to git resource

[bobcatfish]

Expected Behavior

All functionality exposed by the git-init image should be available through the git task.

Actual Behavior

tektoncd/pipeline#2215 added support for proxies to the git PipelineResource but this hasn't been added to the git Task yet.

[ghost]

(Will be) Fixed by #231 I think?

[tekton-robot]

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[tekton-robot]

Stale issues rot after 30d of inactivity.
Mark the issue as fresh with /remove-lifecycle rotten.
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[tekton-robot]

Issues go stale after 90d of inactivity.
Mark the issue as fresh with /remove-lifecycle stale.
Stale issues rot after an additional 30d of inactivity and eventually close.
If this issue is safe to close now please do so with /close.

/lifecycle stale

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[tekton-robot]

@tekton-robot: Closing this issue.

In response to this:

Rotten issues close after 30d of inactivity.
Reopen the issue with /reopen.
Mark the issue as fresh with /remove-lifecycle rotten.

/close

Send feedback to tektoncd/plumbing.

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