gh-36264: `sage --fixdoctests --update-known-test-failures`; silence modularized distributions in CI
    
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The distributions `sagemath-repl` and `sagemath-categories` run parts of
the testsuite in a virtual environment created by `tox` when
SAGE_CHECK=yes. This also runs as part of the Build & Test CI.

Here we make several improvements:
- Support SAGE_CHECK=warn
- Invoke the doctester with `--baseline-stats-path={toxinidir}/known-
test-failures.json`
- Make the tests silent unless new test failures, not recorded in the
`known-test-failures.json`, are encountered

To help maintain the `known-test-failures.json`, we also add new
features to the command `sage --fixdoctests`.
- `sage --fixdoctests --update-known-test-failures` reads the stats
files generated by the doctester in the virtual environments and writes
updated `known-test-failures.json` files to the source tree
- doctester stats now also include a field `ntests` - number of doctests
of a module that were run

`sage --fixdoctests` also receives new switches `--distribution all`,
`--fixed-point`, `--verbose`, `--no-diff` and some other improvements.

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- Part of: #29705
- Cherry-picked from: #35095
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- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

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- Depends on #36263 (merged here)
- Depends on #36238 (merged here)

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URL: #36264
Reported by: Matthias Köppe
Reviewer(s): Kwankyu Lee, Matthias Köppe

Author: Release Manager

build/pkgs/sagemath_objects/spkg-install

@@ -21,9 +21,28 @@ export PIP_FIND_LINKS="file://$SAGE_SPKG_WHEELS"
 DIST_DIR="$(mktemp -d)"
 python3 -m build --outdir "$DIST_DIR"/dist . || sdh_die "Failure building sdist and wheel"
 
-wheel=$(cd "$DIST_DIR" && sdh_store_wheel . && echo $wheel)
+wheel=$(cd "$DIST_DIR" && sdh_store_wheel . >&2 && echo $wheel)
 ls -l "$wheel"
 
 if [ "$SAGE_CHECK" != no ]; then
-    tox -r -v -e sagepython-sagewheels-nopypi-norequirements --installpkg $wheel
+    export TOX_PARALLEL_NO_SPINNER=1
+    echo Running "tox -r -p auto -v --installpkg $wheel"
+    tox -r -p auto -v --installpkg $wheel
+    status=$?
+    case $status:$SAGE_CHECK:$([ -r known-test-failures.json ]; echo $?) in
+        0:*:0)    echo "Passed the test suite (modulo baseline known-test-failures*.json)";;
+        0:*:*)    echo "Passed the test suite";;
+        *:warn:0) echo "Warning: New failures (not in baseline known-test-failures*.json (ignored)"; status=0;;
+        *:warn:*) echo "Warning: Failures testing the package (ignored)"; status=0;;
+        *:yes:0)  echo "New failures, not in baseline known-test-failures*.json";;
+        *:yes:*)  echo "Failures testing the package";;
+    esac
+    # Show summaries of failures (suppress lines ending with '[failed in baseline]')
+    for f in $(pwd)/.tox/sagepython-sagewheels-nopypi-norequirements*/log/*-command*.log; do
+        if [ -r "$f" ]; then
+            echo "$f"
+            grep '^sage -t.*#[^]]*$' "$f"
+        fi
+    done
+    exit $status
 fi