bpo-43269: Remove redundant extern keywords (GH-24605)

diff --git a/Modules/_sqlite/cache.c b/Modules/_sqlite/cache.c
index ec4a22f..8da0a64 100644
--- a/Modules/_sqlite/cache.c
+++ b/Modules/_sqlite/cache.c
@@ -296,7 +296,8 @@ static PyType_Spec cache_spec = {
 };
 PyTypeObject *pysqlite_CacheType = NULL;
 
-extern int pysqlite_cache_setup_types(PyObject *mod)
+int
+pysqlite_cache_setup_types(PyObject *mod)
 {
     pysqlite_NodeType = (PyTypeObject *)PyType_FromModuleAndSpec(mod, &node_spec, NULL);
     if (pysqlite_NodeType == NULL) {
diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 34ba29b..f6a6ef6 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -1927,7 +1927,8 @@ static PyType_Spec connection_spec = {
 
 PyTypeObject *pysqlite_ConnectionType = NULL;
 
-extern int pysqlite_connection_setup_types(PyObject *module)
+int
+pysqlite_connection_setup_types(PyObject *module)
 {
     pysqlite_ConnectionType = (PyTypeObject *)PyType_FromModuleAndSpec(module, &connection_spec, NULL);
     if (pysqlite_ConnectionType == NULL) {
diff --git a/Modules/_sqlite/cursor.c b/Modules/_sqlite/cursor.c
index 9058aab..7486073 100644
--- a/Modules/_sqlite/cursor.c
+++ b/Modules/_sqlite/cursor.c
@@ -1017,7 +1017,8 @@ static PyType_Spec cursor_spec = {
 
 PyTypeObject *pysqlite_CursorType = NULL;
 
-extern int pysqlite_cursor_setup_types(PyObject *module)
+int
+pysqlite_cursor_setup_types(PyObject *module)
 {
     pysqlite_CursorType = (PyTypeObject *)PyType_FromModuleAndSpec(module, &cursor_spec, NULL);
     if (pysqlite_CursorType == NULL) {
diff --git a/Modules/_sqlite/prepare_protocol.c b/Modules/_sqlite/prepare_protocol.c
index ad79332..7d2d7ad 100644
--- a/Modules/_sqlite/prepare_protocol.c
+++ b/Modules/_sqlite/prepare_protocol.c
@@ -55,7 +55,8 @@ static PyType_Spec type_spec = {
 
 PyTypeObject *pysqlite_PrepareProtocolType = NULL;
 
-extern int pysqlite_prepare_protocol_setup_types(PyObject *module)
+int
+pysqlite_prepare_protocol_setup_types(PyObject *module)
 {
     pysqlite_PrepareProtocolType = (PyTypeObject *)PyType_FromModuleAndSpec(module, &type_spec, NULL);
     if (pysqlite_PrepareProtocolType == NULL) {
diff --git a/Modules/_sqlite/row.c b/Modules/_sqlite/row.c
index 97a5a17..f9dfcbd 100644
--- a/Modules/_sqlite/row.c
+++ b/Modules/_sqlite/row.c
@@ -243,7 +243,8 @@ static PyType_Spec row_spec = {
 
 PyTypeObject *pysqlite_RowType = NULL;
 
-extern int pysqlite_row_setup_types(PyObject *module)
+int
+pysqlite_row_setup_types(PyObject *module)
 {
     pysqlite_RowType = (PyTypeObject *)PyType_FromModuleAndSpec(module, &row_spec, NULL);
     if (pysqlite_RowType == NULL) {
diff --git a/Modules/_sqlite/statement.c b/Modules/_sqlite/statement.c
index f179eee..5702627 100644
--- a/Modules/_sqlite/statement.c
+++ b/Modules/_sqlite/statement.c
@@ -480,7 +480,8 @@ static PyType_Spec stmt_spec = {
 };
 PyTypeObject *pysqlite_StatementType = NULL;
 
-extern int pysqlite_statement_setup_types(PyObject *module)
+int
+pysqlite_statement_setup_types(PyObject *module)
 {
     pysqlite_StatementType = (PyTypeObject *)PyType_FromModuleAndSpec(module, &stmt_spec, NULL);
     if (pysqlite_StatementType == NULL) {