[devtools] qunit: only start firefox once per test
The separate profile initialization step doesn't seem necessary anymore.
This was due to the system-wide installation of the "Sage" Firefox
extensions which breaks -url on a fresh profile. Removing this obnoxious
extension allows us to launch Firefox in a standard way.
Related to #5533333.
[MESSAGES CONTROL]
disable-msg = C0301
[VARIABLES]
# Enable / disable this checker
enable-variables = yes
additional-builtins = _, display_name
[BASIC]
required-attributes=
attr-rgx = (w|[a-z_][a-z0-9_]{2,30})
variable-rgx = (w|[a-z_][a-z0-9_]{2,30})$
argument-rgx = (w|[a-z_][a-z0-9_]{2,30})$
[TYPECHECK]
generated-members=debug,info,notice,warning,error,critical,exception