Have build-docs-local do a link check by default

Update all in-tree call sites:

• For the one that's followed by a call to check-doc-links, just delete that call.

• For the one that isn't, add the --no-linkcheck option.

• There are also some references in HACKING.md. Leave them alone.

Part of #91 (closed)

assigned to @Diziet

enabled an automatic merge when the pipeline for e9405383 succeeds

mentioned in commit b0653396

merged