Remove polylith/API mode (#2967)

This removes most of the code used for polylith/API mode.

This removes the `/api` internal endpoints entirely. 

Binary size change roughly 5%: 
```
51437560 Feb 13 10:15 dendrite-monolith-server # old
48759008 Feb 13 10:15 dendrite-monolith-server # new
```

1 files changed, 2 insertions, 17 deletions

diff --git a/setup/config/config_relayapi.go b/setup/config/config_relayapi.go
index 5a6b093d..ba7b7808 100644
--- a/setup/config/config_relayapi.go
+++ b/setup/config/config_relayapi.go
@@ -17,36 +17,21 @@ package config
 type RelayAPI struct {
 	Matrix *Global `yaml:"-"`
 
-	InternalAPI InternalAPIOptions `yaml:"internal_api,omitempty"`
-	ExternalAPI ExternalAPIOptions `yaml:"external_api,omitempty"`
-
 	// The database stores information used by the relay queue to
 	// forward transactions to remote servers.
 	Database DatabaseOptions `yaml:"database,omitempty"`
 }
 
 func (c *RelayAPI) Defaults(opts DefaultOpts) {
-	if !opts.Monolithic {
-		c.InternalAPI.Listen = "http://localhost:7775"
-		c.InternalAPI.Connect = "http://localhost:7775"
-		c.ExternalAPI.Listen = "http://[::]:8075"
-		c.Database.Defaults(10)
-	}
 	if opts.Generate {
-		if !opts.Monolithic {
+		if !opts.SingleDatabase {
 			c.Database.ConnectionString = "file:relayapi.db"
 		}
 	}
 }
 
-func (c *RelayAPI) Verify(configErrs *ConfigErrors, isMonolith bool) {
-	if isMonolith { // polylith required configs below
-		return
-	}
+func (c *RelayAPI) Verify(configErrs *ConfigErrors) {
 	if c.Matrix.DatabaseOptions.ConnectionString == "" {
 		checkNotEmpty(configErrs, "relay_api.database.connection_string", string(c.Database.ConnectionString))
 	}
-	checkURL(configErrs, "relay_api.external_api.listen", string(c.ExternalAPI.Listen))
-	checkURL(configErrs, "relay_api.internal_api.listen", string(c.InternalAPI.Listen))
-	checkURL(configErrs, "relay_api.internal_api.connect", string(c.InternalAPI.Connect))
 }