realpath: implement -E

[sylvestre]

New feature from coreutils 9.8 which caused the realpath test to fail:
#8720 (comment)

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/overlay-headers (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/misc/tee (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/misc/realpath is no longer failing!

[codspeed]

CodSpeed Performance Report

Merging #8757 will not alter performance

_{Comparing sylvestre:realpath-E (cbccc9a) with main (32eef06)}

Summary

✅ 93 untouched
⏩ 1 skipped¹

Footnotes

1. 1 benchmark was skipped, so the baseline result was used instead. If it was deleted from the codebase, click here and archive it to remove it from the performance reports. ↩

[cakebaker]

Congrats! The gnu test tests/misc/realpath is no longer failing!

Great :)