fix: Add shopt -s nullglob to dependencies script (#726)

This prevents processing the unexpanded glob "**/.flattened-pom.xml" in repos which do not flatten any POMs. Source-Author: dpcollins-google <40498610+dpcollins-google@users.noreply.github.com> Source-Date: Sat Jun 19 18:35:58 2021 -0400 Source-Repo: googleapis/synthtool Source-Sha: 87254ac89a9559864c0a245d6b150406439ce3d8 Source-Link: googleapis/synthtool@87254ac

Author: yoshi-automation

.kokoro/dependencies.sh

@@ -14,6 +14,7 @@
 # limitations under the License.
 
 set -eo pipefail
+shopt -s nullglob
 
 ## Get the directory of the build script
 scriptDir=$(realpath $(dirname "${BASH_SOURCE[0]}"))

synth.metadata

@@ -4,7 +4,7 @@
  "git": {
  "name": ".",
  "remote": "https://github.com/googleapis/java-pubsublite.git",
- "sha": "a31803362a60f36d0340a3ba6ebd4f54e432503d"
+ "sha": "14fb550b9a5ba0d93745323048c34b306198912b"
  }
  },
  {
@@ -19,7 +19,7 @@
  "git": {
  "name": "synthtool",
  "remote": "https://github.com/googleapis/synthtool.git",
- "sha": "1c0c698705e668ccb3d68556ae7260f16ce63a6e"
+ "sha": "87254ac89a9559864c0a245d6b150406439ce3d8"
  }
  }
  ],