[spirv] nuke spirv-opt (#3877)

lots of AGILEism in spirv-opt
theres BETTER alternatives like https://github.com/renderbag/re-spirv (im not gonna bother for now, it probably has shitty build system)
it sucks

the IR already resolves most of the shader code to just constant load/stores
Spirv-opt passes do not seem to make such a big difference
only introduce extra latency
like for example cbuf pass in IR already removes a lot of code, that spirv_opt would otherwise miss due to the fact it doesn't have cbuf information

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

Co-authored-by: crueter <crueter@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3877
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Reviewed-by: crueter <crueter@eden-emu.dev>

externals/cpmfile.json

@@ -102,20 +102,6 @@
         "git_version": "1.3.18",
         "find_args": "MODULE"
     },
-    "spirv-tools": {
-        "package": "SPIRV-Tools",
-        "repo": "KhronosGroup/SPIRV-Tools",
-        "sha": "0a7e28689a",
-        "hash": "eadfcceb82f4b414528d99962335e4f806101168474028f3cf7691ac40c37f323decf2a42c525e2d5bfa6f14ff132d6c5cf9b87c151490efad01f5e13ade1520",
-        "git_version": "2025.4",
-        "options": [
-            "SPIRV_SKIP_EXECUTABLES ON"
-        ],
-        "patches": [
-            "0001-netbsd-fix.patch",
-            "0002-allow-static-only.patch"
-        ]
-    },
     "spirv-headers": {
         "package": "SPIRV-Headers",
         "repo": "KhronosGroup/SPIRV-Headers",