Convert payload to Nullable(String)

[joscalv]

No description provided.

[alrocar]

output from CI:

** Detecting changes from last commit ...
** Diffs from current commit 'e5fba9a85c54dc5d3dcf6f380cc560d1c8b7d3af' and new '52eb14f180ad1f30f6211ea6ee212ddde2380cf9':
	modified:	alter_column_to_nullable/datasources/analytics_events.datasource

** Preparing commit ...
** Processing ./datasources/analytics_events.datasource
** Building dependencies

** [DRY RUN] Deploying commit ...
** [DRY RUN] Running 'analytics_events' 

** Deploying commit ...
** Running 'analytics_events' 
** The description or schema of 'analytics_events' has changed.
**   -  MODIFY COLUMN `payload` Nullable(String)
** The Data Source has been correctly updated.
** 'analytics_events' created
** Not pushing fixtures