LuaJIT submodule is bumped to introduce the following changes:
* test: disable LuaJIT CLI tests in lua-Harness suite
* test: set USERNAME env var for lua-Harness suite
* test: adjust lua-Harness tests that use dofile
* test: adjust lua-Harness suite to CMake machinery
* test: add lua-Harness test suite

Within this changeset lua-Harness suite[1] is added to Tarantool
testing. Considering Tarantool specific changes in runtime the suite
itself is adjusted in LuaJIT submodule.

However, Tarantool provides and unconditionally loads TAP module
conflicting with the one used in the new suite. Hence, the Tarantool
built-in module is "unloaded" in test/luajit-test-init.lua.

Furthermore, Tarantool provides UTF-8 support via another built-in
module. Its interfaces differ from the ones implemented in Lua5.3 and
moonjit. At the same time our LuaJIT fork provides no UTF-8 support, so
lua-Harness UTF-8 detector is simply confused with non-nil utf8 global
variable. As a result, utf8 is set to nil in test/luajit-test-init.lua.

There are also some tests launching Lua interpreter, so strict need to
be disabled for their child tests too. Hence `strict.off()` is added to
`progname` (i.e. arg[-1] considering the way Tarantool parses its CLI
arguments) command used in these tests.

[1]: https://framagit.org/fperrad/lua-Harness/tree/a74be27/test_lua



Closes #5844
Part of #4473

Reviewed-by: Sergey Ostanevich <sergos@tarantool.org>
Reviewed-by: Igor Munkin <imun@tarantool.org>
Signed-off-by: Igor Munkin <imun@tarantool.org>