Dem-stitcher

Fixed
* Resolves read_geoid issue [here](https://github.com/ACCESS-Cloud-Based-InSAR/dem-stitcher/issues/96).
* Update geoid url for egm08 (again) creating public bucket for ACCESS processing
* Included egm96 as gtx in the data directory
* egm08 and egm96 data comes from here: https://download.osgeo.org/proj/vdatum/

Fixed
* Check for Earthdata credentials in netrc (adapted from Joe Kennedy/Forrest Williams) resolving isse [83](https://github.com/ACCESS-Cloud-Based-InSAR/dem-stitcher/issues/83)
* when no credentials in netrc are present when requesting data for `nasadem` or `srtm_v3`, there is a human readable error instructing user to update their `~/.netrc`.
* Updates some ruff linting
* Ensures ruff in `environment.yml`
* Ensure single quotes for consistency.
Changed
* egm08 is now using 2.5 deg raster rather than 1 deg.

* Updated URLs for downloading geoids from agisoft.com. Fixes [88](https://github.com/ACCESS-Cloud-Based-InSAR/dem-stitcher/issues/88).

* Multithreading for windowed reading during merge operation
* Add 3.12 support
* Introduce ruffformatting - i.e. add ruff workflow to actions for static analysis and reformat python files.
* Provide separate progress bar for opening dataset, reading tile metadata, and reading tile array.
* Supresses: `RuntimeWarning: invalid value encountered in intersection` from `shapely`

* Fix urls found in pyproject.toml so they correctly link on PyPI

* Updated license in pyproject.toml that was causing pypi to reject upload