Fix shell script installer

[becw]

Starting in Composer 2.2, running vendor/bin/the-build-installer resulted in the following error, even when running the installer from the correct location:

usage: dirname string [...]
Please run this command from your project root.

This seems to be because Composer 2.2.0 included changes to the way scripts in the vendor/bin/ directory are proxied/run, which broke the installer wrapper script. I'm not sure if there's a better way to fix this -- the updated script still assumes that scripts are located in the vendor/bin/ directory.

• Script proxying was added in Composer 2.2.0 -- previously, scripts were symlinked into the vendor/bin/ directory
• The environment variable COMPOSER_BIN_DIR was added in Composer 2.2.2
• The environment variable was changed to COMPOSER_RUNTIME_BIN_DIR in Composer 2.2.7

Testing instructions

composer create-project palantirnet/drupal-skeleton example dev-develop --no-interaction
cd example

# Pause here and update .ddev/config.yaml to change the "name" from "drupal-skeleton" to "example"

composer require palantirnet/the-build:dev-fix-installer-dirname-error
vendor/bin/the-build-installer

# Follow the prompts to set up the site and install Drupal.

--> The project example should be set up, and ddev should be running with the installed site.

[becw]

The way I had to write this script makes me feel like I'm doing something wrong. But, the script can't reliably find phing without being able to reliably find either the vendor/bin/ directory or itself, and between Composer 2.2.0 and previous versions, the script location changed because Composer started wrapping/proxying scripts, and then an env variable was added in 2.2.2, and then the env variable was changed in 2.2.7...... so I'm not sure what else I could have done here.

[eric-schmidt]

@becw This is all working for me! I did also test downgrading Composer to 2.1.0 just to see what would happen now that we're requiring ^2.2.2. It did cause the composer require palantirnet/the-build:dev-fix-installer-dirname-error command to fail out as expected, but I would be curious how it fails once this is merged in and is a part of the composer create-project palantirnet/drupal-skeleton command -- so we may want to test that once this is rolled out, just to see how it communicates the issue.