Remove trailing space from media type for ots mapping

The regular expression in the new test is intended to match the
documented [1] ABNF for a media type:

    type-name = reg-name
    subtype-name = reg-name

    reg-name = 1*127reg-name-chars
    reg-name-chars = ALPHA / DIGIT / "!" /
                     "#" / "$" / "&" / "." /
                     "+" / "-" / "^" / "_"

Closes gh-29746

[1] https://datatracker.ietf.org/doc/html/rfc4288#section-4.2

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/server/MimeMappings.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -128,7 +128,7 @@ public final class MimeMappings implements Iterable<MimeMappings.Mapping> {
 		mappings.add("otg", "application/vnd.oasis.opendocument.graphics-template");
 		mappings.add("oth", "application/vnd.oasis.opendocument.text-web");
 		mappings.add("otp", "application/vnd.oasis.opendocument.presentation-template");
-		mappings.add("ots", "application/vnd.oasis.opendocument.spreadsheet-template ");
+		mappings.add("ots", "application/vnd.oasis.opendocument.spreadsheet-template");
 		mappings.add("ott", "application/vnd.oasis.opendocument.text-template");
 		mappings.add("ogx", "application/ogg");
 		mappings.add("ogv", "video/ogg");

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/server/MimeMappingsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -20,6 +20,7 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.regex.Pattern;
 
 import org.junit.jupiter.api.Test;
 
@@ -135,4 +136,11 @@ class MimeMappingsTests {
 		assertThat(unmodifiable.get("foo")).isNull();
 	}
 
+	@Test
+	void mimeTypesInDefaultMappingsAreCorrectlyStructured() {
+		String regName = "[A-Za-z0-9!#$&.+\\-^_]{1,127}";
+		Pattern pattern = Pattern.compile("^" + regName + "\\/" + regName + "$");
+		assertThat(MimeMappings.DEFAULT).allSatisfy((mapping) -> assertThat(mapping.getMimeType()).matches(pattern));
+	}
+
 }