fix: ignore null in timeline event

[ipcjs]

Some PR timeline arrays can contain null values, which causes downstream parsing errors
Ignoring null entries fixes the parsing error.

for example: TranscodeGroup/docker#23.

[ipcjs]

@microsoft-github-policy-service agree

[alexr00]

@ipcjs that's where the __typename error was coming from? Nice find. Based on the query, that shouldn't be possible:

https://github.com/ipcjs/vscode-pull-request-github/blob/688855c6807e1c505ea2b81585e69360cb3a9781/src/github/queriesShared.gql#L296-L319

GitHub must have changed something. How'd you figure this out?

[ipcjs]

This PR(TranscodeGroup/docker#23) was added to a private Project, maybe that's related?

[alexr00]

/AzurePipelines run

[azure-pipelines]

Azure Pipelines could not run because the pipeline triggers exclude this branch/path.