Explode + delete with merge key does not work

[stevenwdv]

Describe the bug
Exploding and then deleting a key when a merge key/anchor (<<) is present does not delete the key, even if the deletion is unrelated to the merge key.

Version of yq: 4080883 (current master)
Operating system: linux
Installed via: go build

Input Yaml
data1.yml:

x: 37
a: &a:
  b: 42
<<: *a

Command

yq eval 'explode(.) | del(.x)' data1.yml

Actual behavior

{x: 37, a: {b: 42}, b: 42}

Expected behavior

{a: {b: 42}, b: 42}

Additional context
This is a regression compared to the latest release v4.45.4. I bisected the problem to b15ce77.