Assume not skipped by mark if attribute missing
Assume not skipped by mark if attribute missing

Fixes #3074.

davidszotten/pytest,markshao/pytest,alfredodeza/pytest,The-Compiler/pytest,Akasurde/pytest,nicoddemus/pytest,txomon/pytest,tomviner/pytest,tomviner/pytest,nicoddemus/pytest,hackebrot/pytest,The-Compiler/pytest,tareqalayan/pytest,RonnyPfannschmidt/pytest,pfctdayelise/pytest,pytest-dev/pytest,ddboline/pytest