Prepare module for Drupal 10

Hi @arpeggio,
I have have fixed this issue "Prepare module for Drupal 10" and also attached patch,
please review and verify.

The patch does not work because it does not fix the composer.json. Therefore an upgrade is not possiblle to Drupal 10 using composer.

I have uploaded new patch please review.

Verified the patch #6. The patch was applied and working fine. Moving to RTBC.

Updated the Merge request to reflect changes in composer.json and Readme

This will not install correctly using Composer on Drupal 10, see the error results from trying to install 4.0@alpha. I note that when I follow the sourcecode link, the default package is set at 8.x, not 4.0.

Your requirements could not be resolved to an installable set of packages.

Problem 1
- Root composer.json requires drupal/geotimezone ^4.0@alpha -> satisfiable by drupal/geotimezone[4.0.0-alpha1].
- drupal/geotimezone 4.0.0-alpha1 requires drupal/core ^8.7.7 || ^9 -> found drupal/core[8.7.7, ..., 8.9.x-dev, 9.0.0-alpha1, ..., 9.5.x-dev] but these were not loaded, likely because it conflicts with another require.

@arpeggio could you merge the changes, we are stuck in an update process, geo time zone will not install, see #10.

I had to lenient the module in the composer.json with the composer-plugin:
https://github.com/mglaman/composer-drupal-lenient
Then it worked – without the patch.

@tfranz As per your comment, No need for the patch while we are installing using the Composer?

Or the latest version 4.0.0-alpha1 by default working fine. Please share your finding in details.

The patch can`t be applied, because composer first checks the requirements before applying the patches which would fix them …
I think the patch could work when updating from Drupal 9.x:
Install geotimezone, apply the patch, update to Drupal 10.x.

I am running Drupal Core 3.10.3.
When installing geotimezone via Composer like composer require 'drupal/geotimezone:^4.0@alpha' i get the following error:

Your requirements could not be resolved to an installable set of packages.
drupal/geotimezone 4.0.0-alpha1 requires drupal/core ^8.7.7 || ^9 -> found drupal/core[8.7.7, ..., 8.9.x-dev, 9.0.0-alpha1, ..., 9.5.x-dev] but the package is fixed to 10.3.10

When i add drupal/geotimezone to my lenient-list …
"drupal-lenient": {"allowed-list": ["drupal/geotimezone"]}
… i can install geotimezone:
composer require 'drupal/geotimezone:^4.0@alpha'

The patch (which doesn`t add any functional code) is not needed any more, because drupal-lenient overrides the "require": {"drupal/core": "^8.7.7 || ^9"}

I couldn't find an error yet. But this is a workaround and should be fixed in the next version …