Remove unnecessary, WASM-specific code and configurations

[tzimnoch]

See #168 for further details.

The (SetMaxThreads) call is no longer necessary in 3.0.0 and can be removed from all examples, tests, etc.

I only removed it for __linux__ and  __WASM__ flags as I'm not able to test on __APPLE__, but I suspect this call can be removed for all platforms.

[Copilot]

Pull request overview

This PR removes WASM-specific configuration and conditional code paths, primarily by eliminating the custom __WASM__ define from the Bazel build and trimming platform-guarded initialization/workarounds in examples and docs.

Changes:

• Dropped the Bazel __WASM__ define for //:build_wasm and removed related WASM-specific notes from the WASM build documentation.
• Narrowed SetMaxThreads(0) calls in several examples/tests to only run on __APPLE__.
• Removed a WASM-only error handling branch in examples/analyse_play_bin.cpp, always using ErrorMessage().

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
examples/wasm/calc_dd_table_pbn_test.cpp	Restricts SetMaxThreads(0) call to __APPLE__ in the WASM example test.
examples/solve_board.cpp	Restricts SetMaxThreads(0) call to __APPLE__ in the SolveBoard example.
examples/solve_board_pbn.cpp	Restricts SetMaxThreads(0) call to __APPLE__ in the SolveBoardPBN example.
examples/calc_dd_table_pbn.cpp	Restricts SetMaxThreads(0) call to __APPLE__ in the CalcDDtablePBN example.
examples/analyse_play_bin.cpp	Restricts SetMaxThreads(0) call to __APPLE__ and removes WASM-only error formatting fallback.
docs/wasm_build.md	Removes development notes describing the repo-defined __WASM__ macro and WASM-specific stubs.
CPPVARIABLES.bzl	Removes __WASM__ from DDS_LOCAL_DEFINES for the WASM build select() branch.