scbuildstmt: fix ADD COLUMN minimal supported version

Previously, the minimal supported version for stmt `ADD COLUMN` in the
new schema changer was incorrectly labeled as v22.1, but this stmt was
not fully supported and we added much functionality to it in v22.2.
It was incompatible with the version gating elements commit (e.g.
in a mixed version state, if we want to use new schema changer for an
`ADD COLUMN` but the element `IndexColumn` was excluded due to the
gating, then we will run into issues). This PR changes the minimal
supported version of `ADD COLUMN` to v22.2.

Release justification: bug fix

Release note: None

pkg/sql/logictest/testdata/logic_test/new_schema_changer_mixed

@@ -24,6 +24,9 @@ statement ok
 SET use_declarative_schema_changer = unsafe_always;
 
 # Verify that DDL stmts only supported in v22.2 will cause a panic.
+statement error pq: \*tree\.AlterTable not implemented in the new schema changer
+ALTER TABLE testdb.testsc.t ADD COLUMN j INT NOT NULL DEFAULT 30;
+
 statement error pq: \*tree\.AlterTable not implemented in the new schema changer
 ALTER TABLE testdb.testsc.t DROP COLUMN j;
 
@@ -61,9 +64,6 @@ statement error pq: \*tree\.DropIndex not implemented in the new schema changer
 DROP INDEX testdb.testsc.t@idx
 
 # Verify that DDL stmts supported in v22.1 will succeed.
-statement ok
-ALTER TABLE testdb.testsc.t ADD COLUMN j INT NOT NULL DEFAULT 30;
-
 statement ok
 DROP TYPE testdb.testsc.typ;
 

pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table.go

@@ -47,7 +47,7 @@ type supportedAlterTableCommand struct {
 // declarative schema  changer. Operations marked as non-fully supported can
 // only be with the use_declarative_schema_changer session variable.
 var supportedAlterTableStatements = map[reflect.Type]supportedAlterTableCommand{
-	reflect.TypeOf((*tree.AlterTableAddColumn)(nil)):       {fn: alterTableAddColumn, on: true, minSupportedClusterVersion: clusterversion.V22_1},
+	reflect.TypeOf((*tree.AlterTableAddColumn)(nil)):       {fn: alterTableAddColumn, on: true, minSupportedClusterVersion: clusterversion.Start22_2},
 	reflect.TypeOf((*tree.AlterTableDropColumn)(nil)):      {fn: alterTableDropColumn, on: true, minSupportedClusterVersion: clusterversion.Start22_2},
 	reflect.TypeOf((*tree.AlterTableAlterPrimaryKey)(nil)): {fn: alterTableAlterPrimaryKey, on: true, minSupportedClusterVersion: clusterversion.Start22_2},
 	reflect.TypeOf((*tree.AlterTableAddConstraint)(nil)): {fn: alterTableAddConstraint, on: true, extraChecks: func(