…input.

Default is '1'.

…n limited api.

…y to scripts/test.py.

This allows us to build Pyodide wheels using scripts/test.py without involving
Github.

Also in scripts/test.py, added `-s` flag to control use of Py_LIMITED_API.

Addresses #3914.

On some windows machines, the generated C++ code's calls to malloc() and free()
can cause a compilation failure.

Matches today's changes to https://devguide.python.org/versions/.

…TEXT_SEGMENT.

Also improved definitions of TEXT_* constants for mupdf-1.24.x vs later mupdf
versions.

Specifying complement of a bitmask goes wrong if a new enum value is added to
MuPDF, so we now simply use `pymupdf.TEXTFLAGS_SEARCH`.

…r wheels.

.github/workflows/test_mupdf-master-branch.yml
.github/workflows/test_mupdf-release-branch.yml
    Also build pyodide wheel.
scripts/gh_release.py
    Don't special-case pyodide - we used to build with mupdf master branch if
    run as a scheduled Github action.