Add salsa-ci.yml

We're adding this file so we can disable certain unnecessary jobs.

Gbp-Dch: Ignore

debian/salsa-ci.yml

+include:
+  - https://salsa.debian.org/salsa-ci-team/pipeline/raw/master/salsa-ci.yml
+  - https://salsa.debian.org/salsa-ci-team/pipeline/raw/master/pipeline-jobs.yml
+
+variables:
+  # This package is marked 'all', which means that these targets is superficial.
+  SALSA_CI_DISABLE_BUILD_PACKAGE_ANY: 1
+  SALSA_CI_DISABLE_CROSSBUILD_ARM64: 1
+
+  # No compiled code
+  SALSA_CI_DISABLE_BLHC: 1