chore: Note the version to remove the v1 metrics support from the Dat…

…adog Metrics sink (#19017)

Signed-off-by: Jesse Szwedko <jesse.szwedko@datadoghq.com>

docs/DEPRECATIONS.md

@@ -6,6 +6,6 @@ See [DEPRECATION.md](docs/DEPRECATION.md#process) for the process for updating t
 
 ## To be removed
 
-* Support for `v1` series endpoint in the `datadog_metrics` sink should be removed.
+* datadog_v1_metrics v0.35.0 Support for `v1` series endpoint in the `datadog_metrics` sink should be removed.
 * legacy_openssl_provider v0.34.0 OpenSSL legacy provider flag should be removed
 * armv7_rpm v0.34.0 The armv7 RPM packages should be removed (replaced by armv7hl)