don't call \iexec if -shell-escape is turned OFF

See #62, release log:

• a4d06c3 by @yegor256: #62 no iexec if no -shell-esca...
• 005e3ad by @yegor256: #62 ubuntu 22
• e908305 by @yegor256: #62 rultor
• eb9e014 by @yegor256: #62 year up
• 74a0436 by @renovate[bot]: Update JamesIves/github-pages-...
• 21b2d24 by @renovate[bot]: Update actions/checkout digest...
• d623523 by @renovate[bot]: Update teatimeguest/setup-texl...
• 7b81d98 by @renovate[bot]: Update teatimeguest/setup-texl...
• deceda0 by @yegor256: set versions
• 9df900e by @yegor256: typo
• 04b3d16 by @yegor256: link to blog
• 082e207 by @renovate[bot]: Update actions/checkout digest...
• c4eb70f by @renovate[bot]: Update actions/checkout action...

Released by Rultor 2.0-SNAPSHOT, see build log