fix: advanced task environment argument shows deleted environments

[rocketeerbkw]

General Checklist

• Affected Issues have been mentioned in the Closing issues section
• Documentation has been written/updated
• PR title is ready for inclusion in changelog

Database Migrations

n/a

Description

When defining an advanced task argument of type ENV_VAR_NAME_SOURCE or ENVIRONMENT_SOURCE_NAME_EXCLUDE_SELF, the returned list of environments included deleted environments. This results in a list with potentially a lot of duplicated items.

Selecting any of the duplicates is valid, since the environment name is the most important part, but it can be confusing. This PR filters out deleted environments, since there isn't ever a reason to be able to select one.

Closing issues

n/a

[github-actions]

Overview

Image reference	testlagoon/api:main	lagoon/api:ci-latest
- digest	353b0987ad95	f8893fbddf03
- tag	main	ci-latest
- provenance	https://github.com/uselagoon/lagoon.git/commit/7a5630f4a3d391bdf0c5527faaa178d5ba5c89ad
- vulnerabilities
- platform	linux/amd64	linux/amd64
- size	151 MB	182 MB (+31 MB)
- packages	1579	1579
Base Image	node:22-alpine also known as: • 22-alpine3.23 • 22.22-alpine • 22.22-alpine3.23 • jod-alpine • jod-alpine3.23	node:22-alpine also known as: • 22-alpine3.23 • 22.22-alpine • 22.22-alpine3.23 • jod-alpine • jod-alpine3.23
- vulnerabilities