chore: 2.0.0a0 is accidentally identified as 0.0.0 by pack script (#1…

…1388)

The pack script defensively checks if there are any artifacts versioned 0.0.0 under the `dist/` directory. Python artifacts are named like so: `aws_cdk.aws_iotanalytics-2.0.0a0-py3-none-any.whl` and since by default grep uses regular expressions, this matches `grep 0.0.0`.

The fix is to use `-F` so that the search string is not treated as regex.

pack.sh

@@ -84,7 +84,7 @@ cp ${changelog_file} ${distdir}/CHANGELOG.md
 # defensive: make sure our artifacts don't use the version marker (this means
 # that "pack" will always fails when building in a dev environment)
 # when we get to 10.0.0, we can fix this...
-if find dist/ | grep "${marker}"; then
+if find dist/ | grep -F "${marker}"; then
   echo "ERROR: build artifacts use the version marker '${marker}' instead of a real version."
   echo "This is expected for builds in a development environment but should not happen in CI builds!"
   exit 1