Revert "Conversion of Regex syntax to BNF syntax" #36

Job	Run time
Benchmark	5m 16s
Test / Linux (6.0 - jammy)	2m 14s
Test / Linux (nightly-main - jammy)	2m 22s
Test / Linux (6.1 - jammy)	2m 1s
Test / Linux (nightly-6.2 - jammy)	2m 16s
Test / Linux (6.2 - jammy)	1m 57s
Test / macOS (Xcode ${{ matrix.xcode_version }} - ${{ matrix.os_version }} - ${{ matrix.arch }})	0s
Test / Windows (${{ matrix.swift_version }} - windows-2022)	0s
Test / Embedded Swift SDK for Wasm Build (${{ matrix.swift_version }} - ${{ matrix.os_version }})	0s
Test / Swift SDK for Wasm Build (${{ matrix.swift_version }} - ${{ matrix.os_version }})	0s
Test / Static Linux Swift SDK Build (${{ matrix.swift_version }} - ${{ matrix.os_version }})	0s
Soundness / Broken symlinks check	6s
Soundness / Format check	-1s
Soundness / Shell check	51s
Soundness / API breakage check	1m 39s
Soundness / Unacceptable language check	-1s
Soundness / YAML lint check	6s
Soundness / Documentation check	54s
Soundness / License headers check	8s
Soundness / Python lint check	8s
	19m 56s

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