Clean up matrix.json by removing unused boards

Removed multiple board configurations from the matrix.

Author: mysmarthomesus

.github/workflows/matrix.json

@@ -4,83 +4,5 @@
     "defconfig": "ova",
     "architecture": "x86-64",
     "label": "board/ova"
-  },
-  {
-    "id": "generic-x86-64",
-    "defconfig": "generic_x86_64",
-    "architecture": "x86-64",
-    "label": "board/generic-x86-64"
-  },
-  {
-    "id": "generic-aarch64",
-    "defconfig": "generic_aarch64",
-    "architecture": "aarch64",
-    "label": "board/generic-aarch64"
-  },
-  {
-    "id": "khadas-vim3",
-    "defconfig": "khadas_vim3",
-    "architecture": "aarch64",
-    "label": "board/khadas"
-  },
-  {
-    "id": "odroid-c2",
-    "defconfig": "odroid_c2",
-    "architecture": "aarch64",
-    "label": "board/odroid"
-  },
-  {
-    "id": "odroid-c4",
-    "defconfig": "odroid_c4",
-    "architecture": "aarch64",
-    "label": "board/odroid"
-  },
-  {
-    "id": "odroid-m1",
-    "defconfig": "odroid_m1",
-    "architecture": "aarch64",
-    "label": "board/odroid"
-  },
-  {
-    "id": "odroid-m1s",
-    "defconfig": "odroid_m1s",
-    "architecture": "aarch64",
-    "label": "board/odroid"
-  },
-  {
-    "id": "odroid-n2",
-    "defconfig": "odroid_n2",
-    "architecture": "aarch64",
-    "label": "board/odroid"
-  },
-  {
-    "id": "rpi3-64",
-    "defconfig": "rpi3_64",
-    "architecture": "aarch64",
-    "label": "board/raspberrypi"
-  },
-  {
-    "id": "rpi4-64",
-    "defconfig": "rpi4_64",
-    "architecture": "aarch64",
-    "label": "board/raspberrypi"
-  },
-  {
-    "id": "rpi5-64",
-    "defconfig": "rpi5_64",
-    "architecture": "aarch64",
-    "label": "board/raspberrypi"
-  },
-  {
-    "id": "yellow",
-    "defconfig": "yellow",
-    "architecture": "aarch64",
-    "label": "board/yellow"
-  },
-  {
-    "id": "green",
-    "defconfig": "green",
-    "architecture": "aarch64",
-    "label": "board/green"
   }
 ]