Optimize builds to reduce duplicate dependency checks (#8943)

'mtjson' will now build all required pieces when they don't exist

bin/platformio-custom.py

@@ -159,20 +159,22 @@ def load_boot_logo(source, target, env):
 
 # Load the boot logo on TFT builds
 if ("HAS_TFT", 1) in env.get("CPPDEFINES", []):
-    env.AddPreAction('$BUILD_DIR/littlefs.bin', load_boot_logo)
+    env.AddPreAction(f"$BUILD_DIR/{lfsbin}", load_boot_logo)
 
-# Rename (mv) littlefs.bin to include the PROGNAME
-# This ensures the littlefs.bin is named consistently with the firmware
-env.AddPostAction('$BUILD_DIR/littlefs.bin', env.VerboseAction(
-    f'mv $BUILD_DIR/littlefs.bin $BUILD_DIR/{lfsbin}',
-    f'Renaming littlefs.bin to {lfsbin}'
-))
+mtjson_deps = ["buildprog"]
+if platform.name == "espressif32":
+    # Build littlefs image as part of mtjson target
+    # Equivalent to `pio run -t buildfs`
+    target_lfs = env.DataToBin(
+        join("$BUILD_DIR", "${ESP32_FS_IMAGE_NAME}"), "$PROJECT_DATA_DIR"
+    )
+    mtjson_deps.append(target_lfs)
 
 env.AddCustomTarget(
     name="mtjson",
-    dependencies=None,
+    dependencies=mtjson_deps,
     actions=[manifest_gather],
     title="Meshtastic Manifest",
     description="Generating Meshtastic manifest JSON + Checksums",
-    always_build=True,
+    always_build=False,
 )