Feature request: Add suport for expression-based job filters in CircleCI #4883

According to Circle's documentation job filters are deprecated in favor of expression-based job filters. Currently, projen models filters as

export interface Filter {
    readonly branches?: FilterConfig;
    readonly tags?: FilterConfig;
}

You can get around this by doing something like

filters: 'pipeline.git.branch == main' as unknown as WorkflowJob['filters']

But it would be better if we could avoid repeating this across every project using expresion-based job filters.