Server/Content Service fail when deleting non-existing workspace backup (which is a regular case)

[geropl]

Bug description

Server throws:

Error: 2 UNKNOWN: storage: object doesn't exist
    at Object.exports.createStatusError (/app/node_modules/grpc/src/common.js:91:15)
    at Object.onReceiveStatus (/app/node_modules/grpc/src/client_interceptors.js:1209:28)
    at InterceptingListener._callNext (/app/node_modules/grpc/src/client_interceptors.js:568:42)
    at InterceptingListener.onReceiveStatus (/app/node_modules/grpc/src/client_interceptors.js:618:8)
    at callback (/app/node_modules/grpc/src/client_interceptors.js:847:24)

content-service throws: error deleting workspace backup: workspaces/green-gecko-zxdk2tuh/full.tar

This is caused by a missing workspace backup. This itself is an error case for the workspace, but a regular case for the workspace GC. It should just happily move on instead.

Steps to reproduce

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Expected behavior

content-service should happily return without throwing an error.

Example repository

No response

[csweichel]

A single workspace can then block the remainder of the GC run?