refactor: Use std::span over Span

[maflcko]

std::span allows static extents, which is a nice benefit over just Span.

However, the interface of the two isn't identical and requires some more changes than just defining an alias. This is my current draft to compile with std::span. This should be the minimal changes required to get a green CI, but the changes may not be ideal, so this remains a draft.

Also, this requires and is based on #29071, which is blocked on OSS-Fuzz.

In the meantime, changes that make sense on their own, can be split up.

[DrahtBot]

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Conflicts

Reviewers, this pull request conflicts with the following ones:

• #29432 (Stratum v2 Template Provider (take 3) by Sjors)
• #29408 (lint: Check for missing bitcoin-config.h includes by maflcko)
• #29165 (build: Bump clang minimum supported version to 15 by maflcko)
• #29077 ([WIP, DO NOT MERGE!!11111!!!!!] build: Require libc++-16 or later by maflcko)
• #29071 (refactor: Remove Span operator==, Use std::ranges::equal by maflcko)
• #28710 (Remove the legacy wallet and BDB dependency by achow101)
• #28687 ([WIP] C++20 std::views::reverse by stickies-v)
• #26606 (wallet: Implement independent BDB parser by achow101)
• #26596 (wallet: Migrate legacy wallets to descriptor wallets without requiring BDB by achow101)
• #26593 (tracing: Only prepare tracepoint arguments when actually tracing by 0xB10C)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

[obrusvit]

double include

[DrahtBot]

🐙 This pull request conflicts with the target branch and needs rebase.

[DrahtBot]

⌛ There hasn't been much activity lately and the patch still needs rebase. What is the status here?

• Is it still relevant? ➡️ Please solve the conflicts to make it ready for review and to ensure the CI passes.
• Is it no longer relevant? ➡️ Please close.
• Did the author lose interest or time to work on this? ➡️ Please close it and mark it 'Up for grabs' with the label, so that it can be picked up in the future.