Test Red Hat Feed (#2578)

Pushed the Red Hat OSV records to a temporary Github repository for
testing. Actually content will be published to a Rest API as outlined in
the osv-schema PR: ossf/osv-schema#257

Co-authored-by: Oliver Chang <oliverchang@users.noreply.github.com>

osv/ecosystems/_ecosystems.py

@@ -64,6 +64,7 @@
     'Linux': OrderingUnsupportedEcosystem(),
     'OSS-Fuzz': OrderingUnsupportedEcosystem(),
     'Photon OS': OrderingUnsupportedEcosystem(),
+    'Red Hat': OrderingUnsupportedEcosystem,
 }
 
 # Semver-based ecosystems, should correspond to _ecosystems above.

source_test.yaml

@@ -256,6 +256,18 @@
   link: 'https://github.com/RConsortium/r-advisory-database/blob/main/'
   editable: False
 
+- name: 'redhat-stage'
+  versions_from_repo: False
+  type: 0
+  ignore_patterns: ['^(?!RH[BES]{1}A-).*$']
+  repo_url: 'https://github.com/jasinner/redhat-osv.git'
+  detect_cherrypicks: False
+  extension: '.json'
+  db_prefix: ['RHBA-', 'RHEA-', 'RHSA-']
+  ignore_git: False
+  link: 'https://github.com/jasinner/redhat-osv/blob/main/'
+  editable: False
+
 - name: 'rockylinux'
   versions_from_repo: False
   type: 1