Enable adding Ubuntu toolchain PPA by default

[Flamefire]

The default in Boost.CI will be false but some jobs still rely on this, so keep it for now the default.

[cppalliance-bot]

An automated preview of the documentation is available at https://1159.json.prtest2.cppalliance.org/libs/json/doc/html/index.html

If more commits are pushed to the pull request, the docs will rebuild at the same URL.

2026-05-05 12:22:50 UTC

[cppalliance-bot]

GCOVR code coverage report https://1159.json.prtest2.cppalliance.org/gcovr/index.html
LCOV code coverage report https://1159.json.prtest2.cppalliance.org/genhtml/index.html
Coverage Diff Report https://1159.json.prtest2.cppalliance.org/diff-report/index.html

Build time: 2026-05-05 12:44:17 UTC

[cppalliance-bot]

Benchmark test results. More info at https://benchmark.cppalliance.org/jsonbenchmarks-pullrequests/1159/pullrequest.html

[grisumbras]

I decided to go the opposite way in #1158 and just not rely on the PPA by default.

[Flamefire]

That's the best solution, yes.