Export with transparency on Windows

### Describe the bug
I have spent a couple of days working on my animations and exporting them as .mp4 for testing purposes. I thought switching to a .mov format with transparent background would be as easy as adding the -t flag to my manim command, but apparently it’s not.

`manim -qh myfile.py BounceImage
`

works. It produces a .mp4 and I can see my animation (a simple image entering the screen with a bouncing effect, see code below). But with

`manim -tqh myfile.py BounceImage
`

it’s producing a .mov file that can only be opened in VLC and not Premiere ("File import failure: The file has no audio or video stream") neither Windows Media Player, Media Player, Movies & TV ("The file is encoded in rle format which isn’t supported").

Plus, when opened in VLC, I do not see the boucing animation, I just see my image at its final position.

I’m using Manim Community v0.18.0 inside a Conda environment on Windows if it matters.

If it’s a known bug, what would be the best workaround? Can ffmpeg remove the solid background from a .mp4 for instance? Or is it better to export as a series of transparent .png and then use ffmpeg to merge them into a .mov file that can be read by Premiere (which is the final editing software I will be importing into)?

My bouncing effect:

```
class BounceImage(Scene):

def __init__(self, **kwargs):
super().__init__(**kwargs)
self.img_path = "path/to/image.jpg"

def construct(self):
img = ImageMobject(self.img_path)
video_width = config.frame_width
img_width = video_width * 0.4
img.scale_to_fit_width(img_width)

margin = 0.02 * video_width
final_pos = np.array([-config.frame_width / 2 + margin + img_width / 2, config.frame_height / 2 - margin - img.height / 2, 0])

img.move_to(final_pos + 5*UP)
img_start = img.copy()

points = [
final_pos + 5*UP,
final_pos + 2*UP,
final_pos + 0.3*UP,
final_pos - 0.15*UP,
final_pos + 0.15*UP,
final_pos + 0.05*UP,
final_pos,
final_pos - 0.075*UP,
final_pos + 0.075*UP,
final_pos - 0.05*UP,
final_pos
]

path = VMobject().set_points_smoothly(points)

self.play(MoveAlongPath(img_start, path, rate_func=smooth), run_time=1)
self.wait(10)

```

The issue is about the -t flag for transparent .mov export on Windows. Look at the export logic in manim/cli/render/commands.py and the video encoding settings in manim/renderer/opengl_renderer.py or the Cairo/OpenGL renderers. Check how transparency is handled and which ffmpeg codec is used (rle). Test exporting with different codecs and see if the output works in Premiere. The user's code example shows a bouncing image animation; verify the animation renders correctly with transparency.

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