GH-137484: Have Tools/wasm/wasi use the build triple instead of "build"

[brettcannon]

This should help prevent issues where something like a container is used to do one build and then someone tries to build again locally.

• Issue: Use the build triple instead of build for the directory name of the build Python in Tools/wasm/wasi #137484

[brettcannon]

!buildbot wasi

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @brettcannon for commit f71b4d0 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F137485%2Fmerge

The command will test the builders whose names match following regular expression: wasi

The builders matched are:

• wasm32-wasi Non-Debug PR
• wasm32-wasi PR
• wasm32 WASI 8Core PR

[miss-islington-app]

Thanks @brettcannon for the PR 🌮🎉.. I'm working now to backport this PR to: 3.14.
🐍🍒⛏🤖 I'm not a witch! I'm not a witch!

[brettcannon]

It looks like miss-islington had a glitch and didn't leave a comment on the backport PR: #137487

[serhiy-storchaka]

Reminder about backporting. @brettcannon

[brettcannon]

Reminder about backporting. @brettcannon

I have a backport ready to go, but I'm waiting on 3.14 to be unfrozen for general fixes.

[bedevere-app]

GH-137487 is a backport of this pull request to the 3.14 branch.