uo: update license to CC BY 4.0 and add usages (#2933)

* uo: update license to CC BY 4.0 and add usages

The UO repository's LICENSE.md is CC BY 4.0, but this registry entry still
said CC BY 3.0 (and README.md/uo-odk.yaml said CC BY 2.0). The maintainers
have settled on CC BY 4.0 and the ontology header now declares
dcterms:license https://creativecommons.org/licenses/by/4.0/, so the
registry needs to match or the Open check fails on a license mismatch.

Also adds a usages block for FP09. The three listed users all demonstrably
reference UO terms: OBI, the HUPO-PSI mass spectrometry CV, and STATO.

* Standardize uo.md metadata formatting

Run 'python -m obofoundry.standardize_metadata' so the usages block matches
the canonical key ordering enforced by TestStandardizedYaml.

* Update ontology/uo.md

Co-authored-by: Deepak <deepakunni3@users.noreply.github.com>

* Quote UO usage example description containing a colon

The unquoted colon in the dashboard example description broke YAML
parsing in extract-metadata.py (make test). Quoting matches the output
of obofoundry.standardize_metadata.

Claude-Session: https://claude.ai/code/session_01C8W1pJ4TkQ3eeaoEdQeUL8

---------

Co-authored-by: Deepak <deepakunni3@users.noreply.github.com>

Author: leechuck

ontology/uo.md

@@ -11,8 +11,8 @@ description: Metrical units for use in conjunction with PATO
 domain: phenotype
 homepage: https://github.com/bio-ontology-research-group/unit-ontology
 license:
-  label: CC BY 3.0
-  url: http://creativecommons.org/licenses/by/3.0/
+  label: CC BY 4.0
+  url: https://creativecommons.org/licenses/by/4.0/
 preferredPrefix: UO
 products:
 - id: uo.owl
@@ -23,6 +23,27 @@ publications:
   title: 'The Units Ontology: a tool for integrating units of measurement in science'
 repository: https://github.com/bio-ontology-research-group/unit-ontology
 tracker: https://github.com/bio-ontology-research-group/unit-ontology/issues
+usages:
+- description: UO has been used in various OBO ontologies, including the Ontology for Biomedical Investigations (OBI), The Statistical Methods Ontology (STATO), and HUGO-PSI Mass spectrometry ontology (MS).
+  examples:
+  - description: 'List of ontologies using at least one UO term (See section entitled "Info: Which ontologies use it?")'
+    url: http://dashboard.obofoundry.org/dashboard/uo/dashboard.html
+  - description: List of ontologies using the term "length unit" (See section entitled "Ontologies that use the Class")
+    url: https://ontobee.org/ontology/UO?iri=http://purl.obolibrary.org/obo/UO_0000001
+  type: owl_import
+  user: (multiple)
+- description: The Ontology for Biomedical Investigations (OBI) uses UO terms to specify the units of measurement values recorded in investigations.
+  type: ontology
+  user: http://obi-ontology.org/
+- description: The HUPO-PSI mass spectrometry controlled vocabulary (PSI-MS) uses UO terms as the units of the quantitative terms it defines for the mzML and related PSI data standards.
+  publications:
+  - id: https://www.ncbi.nlm.nih.gov/pubmed/23482073
+    title: The HUPO proteomics standards initiative- mass spectrometry controlled vocabulary
+  type: ontology
+  user: https://www.psidev.info/
+- description: STATO, the statistical methods ontology, uses UO terms to type the units of the statistical measures and parameters it defines.
+  type: ontology
+  user: http://stato-ontology.org/
 activity_status: active
 ---