Convert zero-output EXPECT=<<EOF to single-line EXPECT=

[kazarmy]

Your checklist for this pull request

• I've read the guidelines for contributing to this repository
• I made sure to follow the project's coding style
• I've documented or updated the documentation of every function and struct this PR changes. If not so I've explained why.
• I've added tests that prove my fix is effective or that my feature works (if possible)
• I've updated the rizin book with the relevant information (if needed)

Detailed description

Like #4744, this pr converts zero-output EXPECT=<<EOF into single-line EXPECT= because:

1. They take less lines and are faster to read.
2. rz-test -i fixes zero-output stdout into single-line EXPECT=.

Conversion is done using:

(REGEX='EXPECT=<<EOF\nEOF' && grep -rPzl "$REGEX" test/db | xargs -n 1 perl -0777 -i -pe "s/$REGEX/EXPECT=/g")

Test plan

All builds are green.

Closing issues

...