Use patch/build instead of minor/patch in 'versioningTemplate'

According to the documentation 'build' can be used after 'major', 'minor'
and 'patch' have been already used and a fourth version part is needed.

On the other hand, it's only mandatory to use at least one of 'major',
'minor' or 'patch'.

We are using 'patch' and 'build' in compose-images so this change is
to make the versioning consistent among both projects.

Signed-off-by: Miguel Martín <mmartinv@redhat.com>

renovate.json

@@ -49,7 +49,7 @@
         "REPOS_IMAGE=(?<depName>.*):(?<currentValue>.*)@(?<currentDigest>.*)\\n",
         "BUILDER_IMAGE=(?<depName>.*):(?<currentValue>.*)@(?<currentDigest>.*)\\n"
       ],
-      "versioningTemplate": "regex:(?<compatibility>.*)-(?<minor>\\d{8})(\\.n)?\\.(?<build>\\d)",
+      "versioningTemplate": "regex:(?<compatibility>.*)-(?<patch>\\d{8})(\\.n)?\\.(?<build>\\d)",
       "datasourceTemplate": "docker"
     }
   ],