mega-melt: fix bug in skipTests.txt generation

We need to append each line to the existing file.
Because the melting-pot directory is always newly created,
we can just always use >> instead of >, to avoid future bugs
resulting from copy-paste, as my mistake today was.

Author: ctrueden

tests/run.sh

@@ -168,15 +168,15 @@ chmod +x "$meltScript" ||
   die "Failed to adjust $meltScript"
 
 # TEMP: Until imagej/imagej-legacy#285 is fixed.
-echo "net.imagej/imagej-legacy" > "$skipTestsFile" &&
+echo "net.imagej/imagej-legacy" >> "$skipTestsFile" &&
 
 # TEMP: Until saalfeldlab/n5-zarr#11 is merged and released.
-echo "org.janelia.saalfeldlab/n5-zarr" > "$skipTestsFile" &&
+echo "org.janelia.saalfeldlab/n5-zarr" >> "$skipTestsFile" &&
 
 # com.amazonaws.services.s3.model.AmazonS3Exception: The specified bucket does
 # not exist (Service: Amazon S3; Status Code: 404; Error Code: NoSuchBucket;
 # Request ID: null; S3 Extended Request ID: null; Proxy: null)
-echo "org.janelia.saalfeldlab/n5-aws-s3" > "$skipTestsFile" &&
+echo "org.janelia.saalfeldlab/n5-aws-s3" >> "$skipTestsFile" &&
 
 # Error while checking the CLIJ2 installation: null
 echo "sc.fiji/labkit-pixel-classification" >> "$skipTestsFile" ||