Add 'alma' as SourceRecord origin option

Why these changes are being introduced:
With the addition of Alam MARC records, we will need some logic branching to handle these records,
which is the primary purpose of the SourceRecord.origin property.

How this addresses that need:
* Add 'alma' as option for SourceRecord.origin

Side effects of this change:
* None

Relevant ticket(s):
* https://mitlibraries.atlassian.net/browse/GDT-226

harvester/harvest/alma.py

@@ -184,7 +184,7 @@ def create_source_record_from_marc_record(
         )
 
         return identifier, MARC(
-            origin="mit",
+            origin="alma",
             identifier=identifier,
             data=etree.tostring(marc_record.node),
             marc=marc_record,

harvester/records/record.py

@@ -160,7 +160,7 @@ class SourceRecord:
         ogm_repo_config: config dictionary of OGM repository from configuration YAML
     """
 
-    origin: Literal["mit", "ogm"] = field(validator=in_(["mit", "ogm"]))
+    origin: Literal["alma", "mit", "ogm"] = field(validator=in_(["alma", "mit", "ogm"]))
     identifier: str = field(validator=instance_of(str))
     metadata_format: Literal["fgdc", "iso19139", "gbl1", "aardvark", "marc"] = field(
         validator=in_(["fgdc", "iso19139", "gbl1", "aardvark", "marc"])
@@ -474,6 +474,8 @@ def _schema_provider_s(self) -> str:
         For OGM harvests, provider will come from named defined in OGM configuration YAML.
         """
         match self.origin:
+            case "alma":
+                return "MIT Libraries"
             case "mit":
                 return "GIS Lab, MIT Libraries"
             case "ogm":