feat: prevent proxy context cancelled

[krtkvrm]

Expectation

• [x] request cancellation or interruption from client side should not stop processing on shield side

[coveralls]

Pull Request Test Coverage Report for Build 2837820768

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 294 unchanged lines in 11 files lost coverage.
• Overall coverage decreased (-0.1%) to 50.852%

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Files with Coverage Reduction	New Missed Lines	%
internal/api/v1beta1/namespace.go	2	35.63%
internal/store/postgres/group_repository.go	4	76.56%
internal/api/v1beta1/v1beta1.go	8	0%
internal/api/v1beta1/action.go	10	36.96%
internal/api/v1beta1/policy.go	11	37.82%
internal/api/v1beta1/resource.go	12	0%
internal/api/v1beta1/project.go	33	31.82%
internal/api/v1beta1/org.go	36	27.57%
internal/api/v1beta1/group.go	49	0%
internal/api/v1beta1/user.go	64	39.91%
<!--	Total:	294

Totals
Change from base Build 2779265837:	-0.1%
Covered Lines:	2329
Relevant Lines:	4580

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💛 - Coveralls

[mabdh]

@krtkvrm for the PR prefix, is it a feat: or a fix: ?

also, should we create a new issue and link the issue to this PR?