Don't use non-existent dependency

This makes some go tooling, like `go mod tidy`, not work.

Author: owen-mc

go/ql/test/library-tests/semmle/go/dataflow/flowsources/local/database/go.mod

@@ -12,7 +12,6 @@ require (
 	github.com/rqlite/gorqlite v0.0.0-20250128004930-114c7828b55a
 	go.mongodb.org/mongo-driver v1.17.3
 	gorm.io/gorm v1.25.12
-	github.com/nonexistent/sources v0.0.0-20250300000000-000000000000
 )
 
 require (

go/ql/test/library-tests/semmle/go/dataflow/flowsources/local/database/source.ext.yml

@@ -8,4 +8,4 @@ extensions:
       pack: codeql/go-all
       extensible: sourceModel
     data:
-      - ["github.com/nonexistent/sources", "", False, "Source", "", "", "ReturnValue", "database", "manual"]
+      - ["test", "", False, "Source", "", "", "ReturnValue", "database", "manual"]

go/ql/test/library-tests/semmle/go/dataflow/flowsources/local/database/test.ext.yml

@@ -10,4 +10,4 @@ extensions:
       pack: codeql/go-all
       extensible: sourceModel
     data:
-      - ["github.com/nonexistent/sources", "", False, "Source", "", "", "ReturnValue", "database", "manual"]
+      - ["test", "", False, "Source", "", "", "ReturnValue", "database", "manual"]

go/ql/test/library-tests/semmle/go/dataflow/flowsources/local/database/test_Masterminds_squirrel.go

@@ -6,9 +6,12 @@ import (
 	"context"
 
 	"github.com/Masterminds/squirrel"
-	src "github.com/nonexistent/sources"
 )
 
+func Source[T any]() T {
+	return *new(T)
+}
+
 func test_Masterminds_squirrel_QueryRower(ctx context.Context, db squirrel.QueryRower, sqlizer squirrel.Sqlizer) {
 	scanner := db.QueryRow("") // $ source
 
@@ -136,7 +139,7 @@ func test_Masterminds_squirrel_DeleteBuilder(ctx context.Context, builder squirr
 	sink(r32) // $ hasTaintFlow="r32"
 	sink(r33) // $ hasTaintFlow="r33"
 
-	builder2 := src.Source[squirrel.DeleteBuilder]() // $ source
+	builder2 := Source[squirrel.DeleteBuilder]() // $ source
 
 	var r41, r42, r43 string
 	builder2.ScanContext(ctx, &r41, &r42, &r43)
@@ -177,7 +180,7 @@ func test_Masterminds_squirrel_InsertBuilder(ctx context.Context, builder squirr
 	sink(r42) // $ hasTaintFlow="r42"
 	sink(r43) // $ hasTaintFlow="r43"
 
-	builder2 := src.Source[squirrel.InsertBuilder]() // $ source
+	builder2 := Source[squirrel.InsertBuilder]() // $ source
 
 	var r51, r52, r53 string
 	builder2.Scan(&r51, &r52, &r53)
@@ -225,7 +228,7 @@ func test_Masterminds_squirrel_SelectBuilder(ctx context.Context, builder squirr
 	sink(r42) // $ hasTaintFlow="r42"
 	sink(r43) // $ hasTaintFlow="r43"
 
-	builder2 := src.Source[squirrel.SelectBuilder]() // $ source
+	builder2 := Source[squirrel.SelectBuilder]() // $ source
 
 	var r51, r52, r53 string
 	builder2.Scan(&r51, &r52, &r53)
@@ -273,7 +276,7 @@ func test_Masterminds_squirrel_UpdateBuilder(ctx context.Context, builder squirr
 	sink(r42) // $ hasTaintFlow="r42"
 	sink(r43) // $ hasTaintFlow="r43"
 
-	builder2 := src.Source[squirrel.UpdateBuilder]() // $ source
+	builder2 := Source[squirrel.UpdateBuilder]() // $ source
 
 	var r51, r52, r53 string
 	builder2.Scan(&r51, &r52, &r53)

go/ql/test/library-tests/semmle/go/dataflow/flowsources/local/database/vendor/github.com/nonexistent/sources/stub.go

@@ -25,9 +25,6 @@ go.mongodb.org/mongo-driver/mongo
 # gorm.io/gorm v1.25.12
 ## explicit
 gorm.io/gorm
-# github.com/nonexistent/sources v0.0.0-20250300000000-000000000000
-## explicit
-github.com/nonexistent/sources
 # github.com/couchbase/gocbcore/v10 v10.5.4
 ## explicit
 github.com/couchbase/gocbcore/v10