Is one absolved of responsibility before Allah by shunning a person who has repeatedly refused reconciliation and ignored it, despite repeated attempts to draw closer?

The forbidden abandonment (hajr) is refraining from giving salams when meeting due to animosity, and it ceases simply by giving salams. So, if you give salams to the one who has abandoned you and he does not respond, then you are absolved of the forbidden abandonment. The intent of the hadith is to warn against persistence in enmity, and whoever reconciles with his brother but is not accepted, the one who sought reconciliation is forgiven.