Note: there is a bit of potential confusion about the difference between
/resources/builder.inc.sh (the full implementation for builder scripts),
and /resources/build/builder.inc.sh (the source script that builder
scripts should always use).
This allows us to make assumptions that will always be true for builder
scripts that may not be true for other scripts, such as setting base
folder.
Fixes#11324.
* Always `cd "$THIS_SCRIPT_PATH"`
* Remove unnecessary `cd` from all build.sh
* Remove unnecessary `set -eu` from all build.sh (and `# set -x`)
* Replace old build-utils.sh incantation in a few build.sh scripts
This change adds `index.html` to all links that point to test index pages.
This will show the index page instead of the directory listing when
opening locally, identical to the behavior on TC.
