collab: Remove Stripe code (#36275)

This PR removes the code for integrating with Stripe from Collab.

All of these concerns are now handled by Cloud.

Release Notes:

- N/A

crates/collab/src/api/billing.rs

@@ -1,59 +0,0 @@
-use std::sync::Arc;
-use stripe::SubscriptionStatus;
-
-use crate::AppState;
-use crate::db::billing_subscription::StripeSubscriptionStatus;
-use crate::db::{CreateBillingCustomerParams, billing_customer};
-use crate::stripe_client::{StripeClient, StripeCustomerId};
-
-impl From<SubscriptionStatus> for StripeSubscriptionStatus {
-    fn from(value: SubscriptionStatus) -> Self {
-        match value {
-            SubscriptionStatus::Incomplete => Self::Incomplete,
-            SubscriptionStatus::IncompleteExpired => Self::IncompleteExpired,
-            SubscriptionStatus::Trialing => Self::Trialing,
-            SubscriptionStatus::Active => Self::Active,
-            SubscriptionStatus::PastDue => Self::PastDue,
-            SubscriptionStatus::Canceled => Self::Canceled,
-            SubscriptionStatus::Unpaid => Self::Unpaid,
-            SubscriptionStatus::Paused => Self::Paused,
-        }
-    }
-}
-
-/// Finds or creates a billing customer using the provided customer.
-pub async fn find_or_create_billing_customer(
-    app: &Arc<AppState>,
-    stripe_client: &dyn StripeClient,
-    customer_id: &StripeCustomerId,
-) -> anyhow::Result<Option<billing_customer::Model>> {
-    // If we already have a billing customer record associated with the Stripe customer,
-    // there's nothing more we need to do.
-    if let Some(billing_customer) = app
-        .db
-        .get_billing_customer_by_stripe_customer_id(customer_id.0.as_ref())
-        .await?
-    {
-        return Ok(Some(billing_customer));
-    }
-
-    let customer = stripe_client.get_customer(customer_id).await?;
-
-    let Some(email) = customer.email else {
-        return Ok(None);
-    };
-
-    let Some(user) = app.db.get_user_by_email(&email).await? else {
-        return Ok(None);
-    };
-
-    let billing_customer = app
-        .db
-        .create_billing_customer(&CreateBillingCustomerParams {
-            user_id: user.id,
-            stripe_customer_id: customer.id.to_string(),
-        })
-        .await?;
-
-    Ok(Some(billing_customer))
-}