github/workflow: build jimtcl from sources

github/workflow: build jimtcl from sources

JimTCL submodule was deprecated, this patch modifies
the GitHub snapshot action to build from sources instead.

Change-Id: Ie9ab20dbfd70506992d11a91489e82a9fa6e13ce
Signed-off-by: Samuel Obuch <samuel.obuch@espressif.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/8751
Reviewed-by: Marc Schink <dev@zapb.de>
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Erhan Kurubas <erhan.kurubas@espressif.com>