Don't pin msquic version on Alpine

[liveans]

Currently we're pinning msquic version in Alpine helix images as you can see below:

dotnet-buildtools-prereqs-docker/src/alpine/3.20/helix/Dockerfile

Line 18 in 38e30ba

RUN git clone --depth 1 --single-branch --branch v2.4.3 --recursive https://github.com/microsoft/msquic /tmp/msquic

Ideal solution is getting latest release from msquic releases page.
We can do this as explained in here: #1156 (comment)

[lbussell]

[Triage] Related: #1171