Fix single frame publishing for publish job on farm (to Deadline from e.g. Maya)

[BigRoy]

Changelog Description

Fix publishing of single frame render jobs.

Additional info

Why is this suddenly a new issue? It's due to this PR: #908

That actually fixed a long-standing bug... where a plug-in in Deadline would silently and secretly be fixing it, here: https://github.com/ynput/ayon-deadline/blob/368e2510dc3f8dc904168e51f9afa91c1428986c/client/ayon_deadline/plugins/publish/global/validate_expected_and_rendered_files.py#L74-L77

I couldn't fix this "on collect renders" for Maya - because that'd make it fail here where it still expects it to be a list:

ayon-core/client/ayon_core/pipeline/farm/tools.py

Lines 80 to 88 in e5fe964

	for aov, files in expected_files[0].items():
	replaced_files = []
	for f in files:
	replaced_files.append(
	str(f).replace(orig_scene, new_scene)
	)
	new_exp[aov] = replaced_files
	# [] might be too much here, TODO
	instance.data["expectedFiles"] = [new_exp]

This likely also fixes it for other hosts that use instance.data["expectedFiles"] with the value being list[dict[str, list[str]]] (Basically the files per AOV, where the list of filenames is list[str] but the integrator and other areas really want a single str insteaf of list[str] if it's a single frame). One host I know that does so, is Houdini render submissions.

Metadata json before this PR for a single frame:

...
            "representations": [
                {
                    "colorspaceData": {
                        "colorspace": "ACES - ACEScg",
                        "config": {
                            "path": "C:/Users/User/AppData/Local/Ynput/AYON/addons/ayon_ocio_1.1.1/ayon_ocio/configs/OpenColorIOConfigs/aces_1.2/config.ocio",
                            "template": "C:/Users/User/AppData/Local/Ynput/AYON/addons/ayon_ocio_1.1.1/ayon_ocio/configs/OpenColorIOConfigs/aces_1.2/config.ocio"
                        },
                        "display": "ACES",
                        "view": "sRGB"
                    },
                    "ext": "png",
                    "files": [
                        "Main.1001.png"
                    ],
                    "fps": 25.0,
                    "frameEnd": 1001,
                    "frameStart": 1001,
                    "name": "png",
                    "stagingDir": "{root[work]}/ayontest/asset/char_hero/work/modeling/renders/maya/ynts_char_hero_workfileModeling_v281/Main",
                    "tags": []
                }
            ],
...

After this PR:

...
                        "representations": [
                {
                    "colorspaceData": {
                        "colorspace": "ACES - ACEScg",
                        "config": {
                            "path": "C:/Users/User/AppData/Local/Ynput/AYON/addons/ayon_ocio_1.1.1/ayon_ocio/configs/OpenColorIOConfigs/aces_1.2/config.ocio",
                            "template": "C:/Users/User/AppData/Local/Ynput/AYON/addons/ayon_ocio_1.1.1/ayon_ocio/configs/OpenColorIOConfigs/aces_1.2/config.ocio"
                        },
                        "display": "ACES",
                        "view": "sRGB"
                    },
                    "ext": "png",
                    "files": "Main.1001.png",
                    "fps": 25.0,
                    "frameEnd": 1001,
                    "frameStart": 1001,
                    "name": "png",
                    "stagingDir": "{root[work]}/ayontest/asset/char_hero/work/modeling/renders/maya/ynts_char_hero_workfileModeling_v281/Main",
                    "tags": []
                }
            ],
...

Note the files key now being a single string instead of list of frames.

Fixes ynput/ayon-maya#150

Testing notes:

1. Submit single frame render job from maya and houdini
2. It should publish to deadline fine, and the publish job should succeed (with this PR)
   (Without this PR it should fail on deadline publish job)

Tested:

• Maya
• Houdini

[ynbot]

Task linked: AY-6945 Maya->Deadline: Single frame submissions fails to publish

[moonyuet]

I tested in Houdini, it works smoothly as expected with the single frame.

[LiborBatek]

I was successfully publishing the render from maya and publish job finnished ok on DL.

Also got into AYON without any issues...all good!