Inconsistent Symbol Use in XMIR: Allows Both `@` and `φ` Instead of `φ` Only

See #4394, release log:

• 9c3a0c3 by @yegor256: #4394: Update EC2 instance typ...
• 0c88de7 by @yegor256: Merge pull request #4448 from ...
• fa70a61 by @renovate[bot]: chore(deps): update zerocracy/...
• 79820e3 by @yegor256: Merge pull request #4443 from ...
• 0741401 by @yegor256: Merge pull request #4447 from ...
• 92fb095 by @h1alexbel: bug(#4446): passes
• 0fc2bd9 by @yegor256: Merge pull request #4440 from ...
• 53ff209 by @yegor256: Merge pull request #4404 from ...
• 9fb1626 by @yegor256: Merge pull request #4431 from ...
• c446e5a by @renovate[bot]: chore(deps): update crate-ci/t...
• d97ebde by @h1alexbel: bug(#4394): Q to Phi
• 3ab5058 by @h1alexbel: bug(#4394): QQ meta to Phi
• d4c8f22 by @h1alexbel: Merge branch 'master' into 439...
• 7c5896c by @yegor256: Merge pull request #4438 from ...
• 1e80a1b by @yegor256: Merge pull request #4437 from ...
• 6301c40 by @yegor256: Merge pull request #4441 from ...
• 2bddf1a by @renovate[bot]: fix(deps): update dependency o...
• 2aca2fc by @yegor256: Merge pull request #4439 from ...
• 61ea26b by @h1alexbel: bug(#4365): error message upda...
• 619f2cf by @h1alexbel: bug(#4365): comments are optio...
• and 78 more...

Released by Rultor 2.0-SNAPSHOT, see build log