Bug 1901913 - Only consider channels starting with beta- or nightly- to be dated. r=firefox-build-system-reviewers,sergesanspaille

Until recently, beta-YYYY-MM-DD dated channels was the only way to get
specific betas, but now it's possible to use x.y.z-beta.n, but
repack_rust.py doesn't handle that string as a version.

By considering only channels starting with beta- or nightly to be dated,
we allow x.y.z-beta.n to be considered as a version.

Differential Revision: https://phabricator.services.mozilla.com/D213367

taskcluster/scripts/misc/repack_rust.py

@@ -347,7 +347,7 @@ def fetch_manifest(channel="stable", host=None, targets=()):
                 },
             }
         return manifest
-    if "-" in channel:
+    if channel.startswith(("beta-", "nightly-")):
         channel, date = channel.split("-", 1)
         prefix = "/" + date
     else: