Old version of alertmanager

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?

$ curl -s 'https://api.github.com/repos/prometheus/alertmanager/releases?per_page=1' | jq '.[0].name'
"0.23.0 / 2021-08-25"
[dvaneeden@dve-carbon tiup]$ tiup list alertmanager 
Available versions for alertmanager:
Version  Installed  Release                    Platforms
-------  ---------  -------                    ---------
v0.17.0             2020-05-28T18:49:09+08:00  linux/arm64,darwin/amd64,linux/amd64

2. What did you expect to see?

Versions that match

3. What did you see instead?

There is a big gap between the version that tiup offers and the one on GitHub

4. What version of TiUP are you using (tiup --version)?

1.8.2 tiup
Go Version: go1.17.5
Git Ref: v1.8.2
GitHash: a2912cf0470d651ce724e6c4e79871ec772abe38

The problem with this is that the old version is missing newer features like slack integration and may not have all security updates.

Start by reproducing the mismatch with tiup list alertmanager and compare it with the GitHub releases API command shown in the report. Trace where TiUP's available Alertmanager versions and platform data are defined, then update the catalog and verify that the newer releases appear in the listing.