bpo: don't require and send push_id anymore

This ID was not so useful and got in the way of calling the
get_repo_missing job without actually having received a trigger from
gitlab before (bpo.py --auto-get-repo-missing).

.build.postmarketos.org/submit.py

@@ -16,7 +16,6 @@ for key in ["BPO_API_ENDPOINT",
             "BPO_PAYLOAD_FILES",    # one file per line
             "BPO_PAYLOAD_IS_JSON",  # set to "1" to enable
             "BPO_PKGNAME",
-            "BPO_PUSH_ID",
             "BPO_VERSION",          # $pkgver-r$pkgrel
             ]:
     if key not in os.environ:
@@ -43,7 +42,6 @@ is_json = (os.environ["BPO_PAYLOAD_IS_JSON"] == "1")
 # Prepare HTTP headers
 headers = {"X-BPO-Arch": os.environ["BPO_ARCH"],
            "X-BPO-Branch": os.environ["BPO_BRANCH"],
-           "X-BPO-Push-Id": os.environ["BPO_PUSH_ID"],
            "X-BPO-Token": token,
            "X-BPO-Pkgname": os.environ["BPO_PKGNAME"],
            "X-BPO-Version": os.environ["BPO_VERSION"]}