Delete and not equals filter don't work for multiple documents

[zhoujoetan]

Describe the bug
Delete such as del(. | select(.a1=="abc")) and not equals filter such as del(. | select(.a1!="abc")) does not work for yaml files with multiple documents:

Version of yq: 4.27.5
Operating system: mac/
Installed via: pip3 install

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

---
a1: abc
a2: def
---
a1: abd
a2: def

Command
The command you ran:

yq 'del(. | select(.a1=="abc"))' data1.yml

Actual behavior

---
a1: abc
a2: def
---
a1: abd
a2: def

Expected behavior

---
a1: abc
a2: def

Command 2
The command you ran:

yq 'del(. | select(.a1!="abd"))' data1.yml

Actual behavior

---
a1: abc
a2: def
---
a1: abd
a2: def

Expected behavior

---
a1: abc
a2: def

Additional context
Add any other context about the problem here.

[mikefarah]

Thanks for raising, will fix in the next release

[mikefarah]

Fixed in 4.28.2