drop packit configuration file

Packit is not used currently, therefore let's drop its configuration from the
repository. The change can be always reverted if we change our minds.

.packit.yaml

@@ -1,31 +0,0 @@
-# we have the specfile in the root of our repository
-specfile_path: golang-github-osbuild-composer.spec
-# when doing an update in Fedora, we want to copy the spec file and the config file
-synced_files:
-  - osbuild.spec
-  - .packit.yaml
-upstream_package_name: osbuild-composer
-downstream_package_name: golang-github-osbuild-composer
-jobs:
-  # trigger a COPR build for push events in open PRs
-  - job: copr_build
-    trigger: pull_request
-    metadata:
-      targets:
-        - fedora-31-x86_64
-        - fedora-rawhide-x86_64
-  # this is triggered by a commit on src.fedoraproject.org, not Github!
-  # e.g. in case of mass rebuild or automated changes of spec file (e.g. Python packagers)
-  # it will create a PR on Github with changes in synchronized files
-  - job: sync_from_downstream
-    trigger: commit
-  # create a PR on src.fedoraproject.org containing updated spec file and new sources (tarball)
-  # triggered by Github release
-  - job: propose_downstream
-    trigger: release
-    metadata:
-      dist-git-branch: master
-  - job: propose_downstream
-    trigger: release
-    metadata:
-      dist-git-branch: f31