Some "published_at" dates are incorrect for maven versions

It appears that some version dates are incorrect for some Maven Central packages.

For instance, `https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/org.apache.spark:spark-network-shuffle_2.12/versions/3.5.0` returns `"published_at":"1970-01-20T14:37:26.000Z"`.

which is inconsistent with the date provided by [Maven](https://repo.maven.apache.org/maven2/org/apache/spark/spark-network-shuffle_2.12/3.5.0/) (2023-09-09).

Some other examples are below. From manual analysis, the dates appear to all be 1970-01-20.
```
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/io.quarkus:quarkus-smallrye-graphql-client-deployment/versions/2.16.11.Final
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/com.liferay:com.liferay.frontend.theme.styled/versions/4.0.50
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/software.amazon.awssdk:wisdom/versions/2.20.146
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/com.google.api.grpc:grpc-google-cloud-servicedirectory-v1beta1/versions/0.33.0
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/org.noear:solon.logging.simple/versions/2.5.5-M2
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/com.zegreatrob.jsmints:wdio/versions/4.6.27
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/com.github.qq549631030:priority-dialog/versions/1.2.4
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/io.quarkus:quarkus-resteasy-jackson-deployment/versions/2.16.11.Final
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/cn.herodotus.engine:captcha-core/versions/3.1.3.6
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/io.gravitee.apim.repository:gravitee-apim-repository-elasticsearch/versions/4.0.8
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/io.quarkus:quarkus-smallrye-graphql-client-deployment/versions/3.2.6.Final
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/io.quarkus:quarkus-smallrye-reactive-messaging-kotlin/versions/3.2.6.Final
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/com.google.cloud:google-cloud-domains-bom/versions/1.21.0
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/io.quarkus:quarkus-extension-processor/versions/3.2.6.Final
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/com.google.api.grpc:proto-google-cloud-asset-v1p5beta1/versions/0.128.0
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/com.huaweicloud.sdk:huaweicloud-sdk-live/versions/3.1.59
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/io.quarkus:quarkus-mailer/versions/3.4.0
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/io.opentelemetry.instrumentation:opentelemetry-spring-kafka-2.7/versions/1.30.0-alpha
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/com.google.api.grpc:grpc-google-cloud-enterpriseknowledgegraph-v1/versions/0.20.0
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/cloud.piranha:piranha-embedded/versions/23.9.0
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/io.opentelemetry.instrumentation:opentelemetry-kafka-clients-common/versions/1.30.0-alpha
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/com.zegreatrob.testmints:async/versions/10.3.10
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/org.springframework:spring-jdbc/versions/6.0.12
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/io.debezium:debezium-connector-vitess/versions/2.4.0.Beta2
https://packages.ecosyste.ms/api/v1/registries/repo1.maven.org/packages/io.opentelemetry.javaagent.instrumentation:opentelemetry-javaagent-rmi-bootstrap/versions/1.30.0-alpha
```

## Upvote & Fund

- We're using [Polar.sh](https://polar.sh/ecosyste-ms) so you can upvote and help fund this issue.
- We receive the funding once the issue is completed & confirmed by you.
- Thank you in advance for helping prioritize & fund our backlog.

Reproduce the published_at value using the reported packages.ecosyste.ms Maven version endpoint and compare it with the corresponding Maven Central page. Trace the Maven metadata ingestion path to identify why these dates become January 1970, then verify that the listed examples return their actual publication dates.

Written by the indexing model from the issue text.