chore:bump version to 0.12.5 #996

Job	Run time
build-gem	10s
Use gem to package metanorma ubuntu-20.04 Ruby 3.2.6 CC clang-12	17m 0s
Use gem to package metanorma macos-13 Ruby 3.2.6 CC clang	23m 41s
Use gem to package fontist windows-latest Ruby 3.2.6 CC gcc	57m 39s
Use gem to package fontist ubuntu-20.04 Ruby 3.2.6 CC clang-12	15m 5s
Use gem to package metanorma alpine:3.17 Ruby 3.2.6 CC gcc	25m 1s
Use gem to package fontist macos-13 Ruby 3.2.6 CC clang	18m 18s
Use gem to package fontist alpine:3.17 Ruby 3.2.6 CC gcc	22m 35s
Use gem to package metanorma macos-14 Ruby 3.2.6 CC clang	9m 51s
Use gem to package fontist macos-14 Ruby 3.2.6 CC clang	8m 20s
cross-test on ubuntu-22.04	29s
cross-test on ubuntu-24.04	30s
Release gem	0s
	3h 18m 39s

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