Bump version to `0.13.3+ffmpeg.6.1` #313

Job	Run time
build_dynamic_and_test_ubuntu	1m 45s
build_dynamic_and_test_macos	3m 17s
build_dynamic_and_test_windows_pre	2m 25s
build_static_and_test_ubuntu	5m 20s
build_static_and_test_ubuntu_with_system_ffmpeg	1m 30s
build_with_vcpkg_ffmpeg_windows (x86_64-pc-windows-msvc, x64-windows-static, -Ctarget-feature=+cr...	2m 19s
docs_rs_check	1m 1s
build_with_vcpkg_ffmpeg_windows (x86_64-pc-windows-msvc, x64-windows-static-md)	1m 50s
rust_clippy_check_ubuntu	4m 57s
rust_clippy_check_windows	2m 20s
build_with_vcpkg_ffmpeg_windows (x86_64-pc-windows-msvc, x64-windows, true)	2m 32s
rustfmt_check (macos-latest)	22s
build_with_vcpkg_ffmpeg_windows (i686-pc-windows-msvc, x86-windows-static, -Ctarget-feature=+crt-...	1m 45s
rustfmt_check (windows-latest)	33s
build_with_vcpkg_ffmpeg_windows (i686-pc-windows-msvc, x86-windows-static-md)	2m 16s
rustfmt_check (ubuntu-latest)	11s
build_with_vcpkg_ffmpeg_windows (i686-pc-windows-msvc, x86-windows, true)	1m 50s
build_dynamic_and_test_windows	1m 50s
	38m 3s

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