Piping into 'del' doesn't work

[mikefarah]

Describe the bug

Piping into the del operator does not work - del only works properly when run first.

Version of yq: 4.7.0
Operating system: linux
Installed via: binary

Input Yaml
Concise yaml document(s) (as simple as possible to show the bug, please keep it to 10 lines or less)
data1.yml:

container:
  fieldA: keep
  fieldB: keep
  field: delete

Command
The command you ran:

yq e '.container | del(.field)' test.yaml 

Actual behavior

fieldA: keep
fieldB: keep
field: delete

Expected behavior

fieldA: keep
fieldB: keep

Additional context

Found here #790 by @pmorch

[mikefarah]

Fixed in 4.7.1