Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

release: increase IMAGE_SIZE for arm, arm64, riscv

Related to: PR 264032
MFC after: 5 minutes
Sponsored by: Rubicon Communications, LLC ("Netgate")

release: permanently remove the 'reldoc' target and associates

Following 7b1d1a1658ffb69eff93afc713f9e88ed8b20eac, the structure
for the reldoc target has significantly changed as result of the
ASCIIDoctor/Hugo migration. As the release notes related files
on the installation medium are inherently out of date, purge them
entirely.

Discussed within: re, doceng
No objection: re (silence), doceng (silence)
Timeout: 2 weeks
MFC after: 1 week
MFC to: stable/13, stable/12, and stable/11 only
Sponsored by: Rubicon Communications, LLC ("Netgate")

Add PINE64 ROCK64 config for generation of release images