docs: correct testnet Sponsored FPC address + rc.2 version/URL (reproduces #24471)

[AztecBot]

What

Reproduces the changes in #24471 (originally opened from a fork) so it runs under the org's CI/merge tooling. Corrects the testnet Sponsored FPC address and the v4.3.1 versioned getting-started page to the live 5.0.0-rc.2 testnet values.

Two files, +5/−5 (identical to #24471 — resulting blob SHAs e7521e40cef and 56c6a7445df match):

• docs/docs-developers/getting_started_on_testnet.md — SPONSORED_FPC_ADDRESS 0x261366…7880 → 0x1969946536f0c09269e2c75e414eef4e21a76e763c5514125208db33d7d944d7
• docs/developer_versioned_docs/version-v4.3.1/getting_started_on_testnet.md — install/warning version 4.3.1 → 5.0.0-rc.2, NODE_URL https://rpc.testnet.aztec-labs.com → https://v5.testnet.rpc.aztec-labs.com, SPONSORED_FPC_ADDRESS 0x08b888…f765b → the same 0x1969…944d7

Validation

Verified against the live rc.2 testnet (https://v5.testnet.rpc.aztec-labs.com, rollupVersion 2787991301) via node_getContract:

• 0x1969946536…944d7 → deployed (version 2, contractClassId 0x095a9366d37ca82e92326aa9dea8c917d9a9c859ebdf6a116299c5a9e5f7ef3c) — the real Sponsored FPC ✅
• 0x261366…7880 → null (not deployed) — the wrong value previously on next
• 0x08b888…f765b → null (not deployed) — the older wrong value in the versioned page

Notes

• Supersedes fork PR docs: correct Sponsored FPC address in getting started on testnet guide #24471 — that one can be closed in favor of this.
• The same wrong FPC (0x2613…) is also present on v5-next's getting_started_on_testnet.md; a matching correction there is a separate small PR (not included here).

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Created by claudebox · group: slackbot