CI: Fix the git commit range we pass on to gitlint
CI: Fix the git commit range we pass on to gitlint

The check-compliance.py script uses gitlint to verify the commit message
and takes a range of git commits to validate via the env var
${COMMIT_RANGE}.  Previously we used ${SHIPPABLE_COMMIT_RANGE} however
for branches that doesn't get us what we want.  So we move to using
origin/${PULL_REQUEST_BASE_BRANCH}..${COMMIT}.

Signed-off-by: Kumar Gala <a5e5248af4cd4f0ed8c515f61d40a6e2db46a66e@linaro.org>

holtmann/zephyr,explora26/zephyr,rsalveti/zephyr,zephyrproject-rtos/zephyr,erwango/zephyr,explora26/zephyr,finikorg/zephyr,punitvara/zephyr,fbsder/zephyr,sharronliu/zephyr,mbolivar/zephyr,rsalveti/zephyr,bigdinotech/zephyr,Vudentz/zephyr,Vudentz/zephyr,punitvara/zephyr,runchip/zephyr-cc3220,finikorg/zephyr,nashif/zephyr,mbolivar/zephyr,GiulianoFranchetto/zephyr,zephyriot/zephyr,nashif/zephyr,explora26/zephyr,ldts/zephyr,pklazy/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,runchip/zephyr-cc3220,erwango/zephyr,bigdinotech/zephyr,pklazy/zephyr,Vudentz/zephyr,punitvara/zephyr,finikorg/zephyr,kraj/zephyr,sharronliu/zephyr,erwango/zephyr,sharronliu/zephyr,galak/zephyr,fractalclone/zephyr-riscv,nashif/zephyr,kraj/zephyr,fractalclone/zephyr-riscv,holtmann/zephyr,bigdinotech/zephyr,aceofall/zephyr-iotos,zephyrproject-rtos/zephyr,pklazy/zephyr,rsalveti/zephyr,fractalclone/zephyr-riscv,mbolivar/zephyr,fractalclone/zephyr-riscv,fbsder/zephyr,fbsder/zephyr,pklazy/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,mbolivar/zephyr,aceofall/zephyr-iotos,zephyriot/zephyr,sharronliu/zephyr,galak/zephyr,holtmann/zephyr,runchip/zephyr-cc3220,finikorg/zephyr,Vudentz/zephyr,aceofall/zephyr-iotos,holtmann/zephyr,aceofall/zephyr-iotos,GiulianoFranchetto/zephyr,explora26/zephyr,ldts/zephyr,zephyriot/zephyr,pklazy/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,galak/zephyr,punitvara/zephyr,fractalclone/zephyr-riscv,bigdinotech/zephyr,galak/zephyr,ldts/zephyr,erwango/zephyr,runchip/zephyr-cc3220,sharronliu/zephyr,GiulianoFranchetto/zephyr,erwango/zephyr,bigdinotech/zephyr,rsalveti/zephyr,runchip/zephyr-cc3220,fbsder/zephyr,mbolivar/zephyr,GiulianoFranchetto/zephyr,holtmann/zephyr,kraj/zephyr,rsalveti/zephyr,kraj/zephyr,finikorg/zephyr,Vudentz/zephyr,Vudentz/zephyr,galak/zephyr,zephyriot/zephyr,zephyriot/zephyr,kraj/zephyr,nashif/zephyr,nashif/zephyr,fbsder/zephyr,GiulianoFranchetto/zephyr,aceofall/zephyr-iotos