Bump version to 0.10.3 #204

Job	Run time
Check on Windows	1m 32s
Check on Linux	21s
Clippy	17s
Documentation check	22s
Rustfmt	16s
Test Suite on Linux	1m 14s
Test Suite on Linux (index-positions)	1m 4s
Test Suite on Windows	2m 14s
Test Suite on Linux (prohibit-unsafe)	1m 23s
Test Suite on Windows (index-positions)	2m 26s
Test Suite on Linux (utf16)	1m 32s
Test Suite on Windows (prohibit-unsafe)	2m 18s
Test Suite on Linux (index-positions,prohibit-unsafe)	59s
Test Suite on Windows (utf16)	2m 42s
Test Suite on Linux (index-positions,utf16)	1m 10s
Test Suite on Windows (index-positions,prohibit-unsafe)	3m 12s
Test Suite on Linux (prohibit-unsafe,utf16)	1m 30s
Test Suite on Windows (index-positions,utf16)	2m 53s
Test Suite on Linux (index-positions,prohibit-unsafe,utf16)	1m 16s
Test Suite on Windows (prohibit-unsafe,utf16)	2m 40s
Test Suite on Windows (index-positions,prohibit-unsafe,utf16)	2m 40s
	34m 1s

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