Updates the directed graph component to render custom templates within an '<ng-container>' rather than '<ng-template>' to fix a rendering issue when using Angular Ivy.
Updates the directed graph component to render custom templates within an '<ng-container>' rather than '<ng-template>' to fix a rendering issue when using Angular Ivy.

PiperOrigin-RevId: 366361645

google/angular-directed-graph,google/angular-directed-graph