[cmake, tools, docs] Update CPMUtil (#2790)

updates CPMUtil to
[`8f9b39fc98`](https://git.crueter.xyz/CMake/CPMUtil/commit/8f9b39fc980fc7079c7c4471c19f219180abe368)

Makes the tooling/docs better and enforces usage of tar.gz everywhere as
opposed to zips

Signed-off-by: crueter <crueter@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2790
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

externals/ffmpeg/cpmfile.json

@@ -2,7 +2,7 @@
     "ffmpeg": {
         "repo": "FFmpeg/FFmpeg",
         "sha": "c2184b65d2",
-        "hash": "2a89d664119debbb3c006ab1c48d5d7f26e889f4a65ad2e25c8b0503308295123d5a9c5c78bf683aef5ff09acef8c3fc2837f22d3e8c611528b933bf03bcdd97",
+        "hash": "007b1ccdd4d3ea3324835258d9a255103253bd66edb442b12d9c60dca85149cad52136a3b3120e5094115b6a3d9e80eeacbf9c07e5ffafc9ac459614d5fa3b22",
         "bundled": true
     },
     "ffmpeg-ci": {