feat(lws): bump submodule for mbedTLS 4 support; allow IDF v6.0

[vikramdattu]

Summary

• Bump libwebsockets submodule from `a74362ff` → `7726361c` (warmcat main HEAD) which carries Andy Green's mbedTLS 4 migration commits (`3079d311 mbedtls4` + `7726361 sai-fixes` completing it).
• Drop the `idf <6.0` cap from `idf_component.yml` — IDF v6.0 ships mbedTLS 4 by default and the bumped libwebsockets supports it. Component version `4.3.31` → `4.3.32`.

Verification

• `examples/client` builds clean on IDF release/v6.0 (target esp32) — exit 0, full link.
• No release tag of libwebsockets carries mbedTLS 4 support yet (v4.5.8 predates the migration); pinning by SHA is the only option until warmcat cuts a tag.

Notes

• Sequenced after PR feat(lws): add Kconfig toggles + bump submodule #1061 (libwebsockets Kconfig + 4.3-stable bump). feat(lws): add Kconfig toggles + bump submodule #1061 stays on 4.3-stable; this PR moves to main.

[vikramdattu]

Hi @david-cermak — heads up on the clang-tidy failure: it's not the
code in this PR, it's an upstream libwebsockets bug.

At the SHA we pin (7726361c) — and at every SHA after a68609413 "qpack" (May 20) — the tree declares a gitlink
minimal-examples-lowlevel/api-tests/api-test-qpack/qifs but ships no
.gitmodules file. So git submodule update --init --recursive
fails. I checked: .gitmodules was never in the repo; Andy Green
added the gitlink without registering it. Bisecting to an earlier
lws SHA can't escape it without losing the mbedtls4 commit.

I've filed the upstream fix: warmcat/libwebsockets#3597.

Two paths:

1. Wait for the warmcat maintainer to review and merge #3597 — could
   be a few days.
2. Interim workaround in this PR's CI: replace the recursive
   submodule init with explicit per-component non-recursive inits
   (scoped to lws, doesn't touch asio/mosquitto).

Which do you prefer?

[david-cermak]

• Wait for the warmcat maintainer to review and merge #3597 — could
  be a few days.
• Interim workaround in this PR's CI: replace the recursive
  submodule init with explicit per-component non-recursive inits
  (scoped to lws, doesn't touch asio/mosquitto).

Both options are fine with me. If the upstream fix gets merged within days, I would wait.

[vikramdattu]

@david-cermak the version and the changelog above will pick the commit title automatically?

[david-cermak]

@vikramdattu see https://github.com/espressif/esp-protocols/blob/master/CONTRIBUTING.md#release-process

the commit (when created by the bump command) will update the version files and changelog (based on commit delta from the previous tag)

[david-cermak]

when created by the bump command

but that doesn't support these ~postfix numbers (yet), so you'd need to edit the commit.

Here's an example #1071

PS: If you like, we can merge #1071 to release v4.3.3~2 for now, and after the upstream maintainers fix the above, we can merge this one to release v4.3.3~3

[vikramdattu]

Rebase needed once warmcat/libwebsockets#3600 and warmcat/libwebsockets#3601 and warmcat/libwebsockets#3602 are merged