ci/ci: enable ptest-pkgs image features

Adding "ptest-pkgs" to IMAGE_FEATURES causes all -ptest packages
to be additionally installed.
To exercise the installed unit testing, we simply run ptest-runner.

Ptests won't work with sota, and it is even removed from distro features.
So it doesn't make sense to enable it in this case.

Here are the results for `ci/qcom-armv8a.yml:ci/qcom-distro.yml`

Before this PR:
```
31G build/tmp/deploy/images/qcom-armv8a

1.6G qcom-container-orchestration-image-qcom-armv8a.rootfs.ext4.gz
0.7G qcom-multimedia-image-qcom-armv8a.rootfs.ext4.gz
1.4G qcom-multimedia-proprietary-image-qcom-armv8a.rootfs.ext4.gz
```

After this PR:
```
48G  build/tmp/deploy/images/qcom-armv8a

2.4G qcom-container-orchestration-image-qcom-armv8a.rootfs.ext4.gz
1.5G qcom-multimedia-image-qcom-armv8a.rootfs.ext4.gz
2.1G qcom-multimedia-proprietary-image-qcom-armv8a.rootfs.ext4.gz
```

Signed-off-by: Jose Quaresma <jose.quaresma@oss.qualcomm.com>

Author: quaresmajose

ci/ci.yml

@@ -8,5 +8,7 @@ header:
 local_conf_header:
   ci: |
     BB_SIGNATURE_HANDLER = "OEBasicHash"
+    EXTRA_IMAGE_FEATURES += "ptest-pkgs"
+    EXTRA_IMAGE_FEATURES:remove:sota = "ptest-pkgs"
     FIRMWARE_COMPRESSION:qcom-armv8a = "zst"
     INHERIT:remove = "rm_work"