saga: 6.2.0 -> 6.3.0

Semi-automatic update generated by https://github.com/ryantm/nix-update tools.

This update was made based on information from https://repology.org/metapackage/saga/versions.

These checks were done:

- built on NixOS
- ran `/nix/store/2wk34cz1vvl58pzw8szv4fdy5qwcc1g9-saga-6.3.0/bin/saga_cmd -h` got 0 exit code
- ran `/nix/store/2wk34cz1vvl58pzw8szv4fdy5qwcc1g9-saga-6.3.0/bin/saga_cmd --help` got 0 exit code
- ran `/nix/store/2wk34cz1vvl58pzw8szv4fdy5qwcc1g9-saga-6.3.0/bin/saga_cmd -v` and found version 6.3.0
- ran `/nix/store/2wk34cz1vvl58pzw8szv4fdy5qwcc1g9-saga-6.3.0/bin/saga_cmd --version` and found version 6.3.0
- ran `/nix/store/2wk34cz1vvl58pzw8szv4fdy5qwcc1g9-saga-6.3.0/bin/saga_cmd -h` and found version 6.3.0
- ran `/nix/store/2wk34cz1vvl58pzw8szv4fdy5qwcc1g9-saga-6.3.0/bin/saga_cmd --help` and found version 6.3.0
- found 6.3.0 with grep in /nix/store/2wk34cz1vvl58pzw8szv4fdy5qwcc1g9-saga-6.3.0
- found 6.3.0 in filename of file in /nix/store/2wk34cz1vvl58pzw8szv4fdy5qwcc1g9-saga-6.3.0
- directory tree listing: https://gist.github.com/338621d772f5e116a34641ab1a84ee1e