Release v1.7.3 adding the Echo ecosystem (#402)

Also updated the changelog to include changes from v1.7.2 (we added a
lot of ecosystems!)

Test Rendered here: https://another-rex.github.io/osv-schema/

Signed-off-by: Rex P <rexpan@google.com>

Author: another-rex

CHANGELOG.md

@@ -39,3 +39,5 @@
 - 2024-09-16 Released version 1.6.7. JSON schema and minor text formatting changes.
 - 2025-03-05 Released version 1.7.0. Add `upstream` field, `V8-` ID prefix,
   Kubernetes ecosystem, `Ubuntu` severity type.
+- 2025-08-05 Released version 1.7.2. Add new ecosystems (openEuler, MinimOS, BellSoft Alpaquita and Hardened Containers, Ubuntu LSN).
+- 2025-08-15 Released version 1.7.3. Add Echo ecosystem.

bindings/go/osvschema/constants.go

@@ -1,6 +1,6 @@
 package osvschema
 
-const SchemaVersion = "1.7.0"
+const SchemaVersion = "1.7.3"
 
 type Ecosystem string
 

docs/schema.md

@@ -8,7 +8,7 @@ aside:
 show_edit_on_github: true
 ---
 
-**Version 1.7.2 (June 23, 2025)**
+**Version 1.7.3 (August 15, 2025)**
 
 Original authors:
 - Oliver Chang (ochang@google.com)