Support resource patterns in @TestPropertySource locations

Inspired by the recently added support for resource patterns in
@PropertySource locations, this commit adds the same support for
resource locations in @TestPropertySource.

For example, assuming the `config` folder in the classpath contains
only 3 files matching the pattern `file?.properties`,

... the following:

@TestPropertySource("classpath:/config/file1.properties")
@TestPropertySource("classpath:/config/file2.properties")
@TestPropertySource("classpath:/config/file3.properties")

... or:

@TestPropertySource({
    "classpath:/config/file1.properties",
    "classpath:/config/file2.properties",
    "classpath:/config/file3.properties"
})

... can now be replaced by:

@TestPropertySource("classpath*:/config/file?.properties")

See gh-21325
Closes gh-31055

spring-test/src/test/java/org/springframework/test/context/env/ResourcePatternExplicitPropertiesFileTests.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.test.context.env;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
+import org.springframework.test.context.TestPropertySource;
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Integration tests for {@link TestPropertySource @TestPropertySource} support
+ * for resource patterns for resource locations.
+ *
+ * @author Sam Brannen
+ * @since 6.1
+ */
+@SpringJUnitConfig
+@TestPropertySource("classpath*:/org/springframework/test/context/env/pattern/file?.properties")
+class ResourcePatternExplicitPropertiesFileTests {
+
+	@Test
+	void verifyPropertiesAreAvailableInEnvironment(@Autowired Environment env) {
+		assertEnvironmentContainsProperties(env, "from.p1", "from.p2", "from.p3");
+	}
+
+
+	private static void assertEnvironmentContainsProperties(Environment env, String... names) {
+		for (String name : names) {
+			assertThat(env.containsProperty(name)).as("environment contains property '%s'", name).isTrue();
+		}
+	}
+
+
+	@Configuration
+	static class Config {
+		/* no user beans required for these tests */
+	}
+
+}