Remove stty echo workaround

Note that the run script is now entirely deprecated, since the host can be run directly.

pester.sh

@@ -1,5 +1,3 @@
 ./bin/Microsoft.PowerShell.Linux.Host -c "Invoke-Pester src/pester-tests/$1 -OutputFile pester-tests.xml -OutputFormat NUnitXml"
 # XML files are not executable
 chmod -x pester-tests.xml
-# Fix tty due to possible bug in .NET
-stty echo || true

run.sh

@@ -1,3 +0,0 @@
-./bin/Microsoft.PowerShell.Linux.Host $@
-# Fix tty due to possible bug in .NET
-stty echo