Lack of action is not an active disruption. You not being healed doesn’t disrupt your play, otherwise DPS who misses their shots or anyone who miss a team fight are also guilty of sabotage.
Blizzard has also further stated:
For a player to be reported for Gameplay Sabotage, they must intentionally be trying to disrupt and harass their teammates or actively trying to lose.
A support who isn’t healing you isn’t trying to disrupt your play. At most they are ignoring you. Ignoring you isn’t a reportable offense.