PTBP1 and myocardial infarction: Methyltransferase‐like 3 (METTL3) modifies m6A methylation to facilitate the binding of lncRNA‐SNHG8 and polyrimidine tract binding protein 1 (PTBP1), thus regulating ALAS2 expression, increasing oxidative stress, and promoting myocardial infarction