Optimize builds to reduce duplicate dependency checks (#8943)

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

bin/build-nrf52.sh

@@ -22,7 +22,7 @@ export APP_VERSION=$VERSION
 
 basename=firmware-$1-$VERSION
 
-pio run --environment $1 # -v
+pio run --environment $1 -t mtjson # -v
 
 cp $BUILDDIR/$basename.elf $OUTDIR/$basename.elf
 
@@ -47,8 +47,5 @@ if (echo $1 | grep -q "rak4631"); then
 	cp $SRCHEX $OUTDIR/
 fi
 
-# Generate the manifest file
-echo "Generating Meshtastic manifest"
-TIMEFORMAT="Generated manifest in %E seconds"
-time pio run --environment $1 -t mtjson --silent --disable-auto-clean
+echo "Copying manifest"
 cp $BUILDDIR/$basename.mt.json $OUTDIR/$basename.mt.json