.github: Don't run CodeQL for every master push
.github: Don't run CodeQL for every master push

We are limited to 20 concurrent GitHub jobs and that limit is frequently
reached, leading to long queues. The CodeQL job takes between 17 and 25
minutes so it has a non-negligible impact.

We already run that job on every pull request and once a day. CodeQL
performs a static analysis so it's not hard to figure out where the bug
is when a bug is reported (vs. end-to-end tests where it may be useful
to run on every single commit). This commit therefore removes the
CodeQL trigger for every master push.

The fail-fast strategy is also removed as it seems to only apply to
matrix jobs anyway [1]. In any case, the jobs in the CodeQL workflow
each depend on previous jobs succeeding.

1 - https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#jobsjob_idstrategyfail-fast
Signed-off-by: Paul Chaignon <a027184a55211cd23e3f3094f1fdc728df5e0500@cilium.io>

cilium/cilium,tklauser/cilium,michi-covalent/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,tklauser/cilium,cilium/cilium,tklauser/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium