Remove partition-reference from .fossa-yml modules

The partition-reference module was removed from the code with dc9a9eb6, but the fossa configuration was missed. As a result, the
fossa-analyze steps were failing, unable to list dependencies in the non-existent project.

.fossa.yml

@@ -32,7 +32,3 @@ analyze:
     type: mvn
     target: provider/partition-gcp/pom.xml
     path: .
-  - name: partition-reference
-    type: mvn
-    target: provider/partition-reference/pom.xml
-    path: .