Fix truncation tests: pyruntest() match
Fix truncation tests: pyruntest() match

Fix issue with truncation tests for -vv and CI, where the test for
non-truncated output would return a positive match even on truncated output.

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