fix: Add shopt -s nullglob to dependencies script (#392)

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

.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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-shared-dependencies.git",
-        "sha": "7b1d4cf317fbd75b91d6a63f82b5fc2f46eaf3ca"
+        "sha": "7b87c9aff5604dd894296a641fb34a3e8a73395c"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "1c0c698705e668ccb3d68556ae7260f16ce63a6e"
+        "sha": "87254ac89a9559864c0a245d6b150406439ce3d8"
       }
     }
   ],