EnvironmentBlock replaced every non-ASCII character of an inherited name
with '?' before asking whether to withhold it, so --pass-env=MY_?_TOKEN
kept an unrelated MY_é_TOKEN. Names are now converted with Narrow, as
everything else the runner compares.

A block whose variables were all withheld, with no additions, ended in one
terminator; CreateProcessW needs two for an empty block.

The amalgamated sources are regenerated for the runner changes.

The scripts in use become programs run with `bazelisk run //tools:<tool>`,
and arguments follow `--`:

  amalgamate     the single-file distribution; --check only compares it
  check          licenses, convenience headers, header guards, file names,
                 versions and whether the distribution is up to date
  third-party    compares third_party/ with its archives, or writes it
  version        prints the version, or moves every place that states it
  release-notes  prints a section of the release notes
  repo-info      reports the checkout and the tools on PATH; --json writes
                 it through yyjson, with the fields of Tala's repo-info

amalgamate writes what the Python script wrote, byte for byte, except for
the time of generation. That line is gone so that the output is
deterministic and --check can compare it.

MODULE.bazel now pins the archives of third_party/ by version and sha256,
so Bazel fetches and checks them instead of a tool of ours, and Renovate
reads the versions there.

Scripts nobody used are gone: fixWhitespace, updateDocumentSnippets,
buildAndTest, and updateDocumentToC, which rewrote unrelated documents.
CheckConvenienceHeaders leaves CTest, since //tools:check runs it in CI.
The Python of tests/TestScripts stays: those are tests, not tools.

Mock.hpp goes into catch_amalgamated.hpp, since tests use it directly, and
Mock.cpp into catch_amalgamated.cpp. The test of the amalgamated files
now uses a mock, so a file left out fails it.

A report no longer throws, so a noexcept mock survives an aborting run.
A call that has nothing to return still leaves the test case, which ends
the process in a noexcept function; the documentation says so.

RunContext clears the result capture when it goes, so a mock of static
lifetime finds none and writes to standard error.

Decision owns its source line, since Verify can free the expectation
while a call is on its way. Moving a result out takes the lock. Vector
matchers refer to their vector, so they are rejected at compile time
like composed ones. A null text expectation accepts only null, and
integers compare by value, so 256 no longer accepts an unsigned char.

Versions have four numbers from this release on.

A review of the import found ways for a failure to disappear or for the
import to reach too far.

- CTRF's retryAttempts ends before the final attempt, which was dropped when
  its outcome matched the one before it.
- TAP names tests only within a stream, so a failure in one file and a pass
  under the same name in another merged into a flaky pass. The path given to
  --import is now the class of a stream's tests.
- A failure followed by a skip with the same identifier read as skipped.
- Directives are whole words: TODOING is not TODO. SKIPPED and SKIPPING stay
  directives, as harnesses treat them.
- Verdicts that alternate count as flaky only under an explicit
  --import-revision. HEAD says nothing about a dirty checkout or a report from
  another one, and two such events could quarantine a real failure.
- --import-name no longer redirects the history of a normal test run.
- Importing does not depend on the tests registered in the binary.

Tests Catch3 does not run had no history, flaky detection or quarantine.
--import=FILE reads a report instead of running tests and sends it through
the analysis, history and reports of a run: JUnit with Surefire's reruns,
xUnit.net v2, TRX, TAP 12 to 14, CTRF, Catch3's own --json report and
catch3-results, a small JSON Lines format for tools with none of these.

Results that share an identifier are attempts at one test, so a report of a
rerun gives a flaky test. --import-revision says what was tested: a verdict
that changes on one revision also counts as flaky. --import-name keeps the
results in a history of their own, which --analytics reads too. A TAP stream
that ends early fails instead of reading as a run that passed.

The amalgamation script now accepts a relative include of the third-party
wrappers, because pugixml is included from a second directory.