Remove trailing spaces in default UIs

- Default UIs had blank lines with only spaces. These get deleted by the
  spring-javaformat plugin. In order to avoid this behavior, an extra \s
  had been inserted in the tests. The reason for those \s is not obvious.
- This commit cleans up the \s but changing the HTML templates.

config/src/test/java/org/springframework/security/config/annotation/web/configurers/DefaultLoginPageConfigurerTests.java

@@ -105,7 +105,7 @@ public class DefaultLoginPageConfigurerTests {
 						    <div class="content">
 						      <form class="login-form" method="post" action="/login">
 						        <h2>Please sign in</h2>
-						       \s
+
 						        <p>
 						          <label for="username" class="screenreader">Username</label>
 						          <input type="text" id="username" name="username" placeholder="Username" required autofocus>
@@ -286,7 +286,7 @@ public class DefaultLoginPageConfigurerTests {
 						    <div class="content">
 						      <form class="login-form" method="post" action="/login">
 						        <h2>Please sign in</h2>
-						       \s
+
 						        <p>
 						          <label for="username" class="screenreader">Username</label>
 						          <input type="text" id="username" name="username" placeholder="Username" required autofocus>

config/src/test/java/org/springframework/security/config/annotation/web/configurers/ott/OneTimeTokenLoginConfigurerTests.java

@@ -150,7 +150,7 @@ public class OneTimeTokenLoginConfigurerTests {
 						    <div class="content">
 						      <form class="login-form" method="post" action="/login">
 						        <h2>Please sign in</h2>
-						       \s
+
 						        <p>
 						          <label for="username" class="screenreader">Username</label>
 						          <input type="text" id="username" name="username" placeholder="Username" required autofocus>
@@ -165,7 +165,7 @@ public class OneTimeTokenLoginConfigurerTests {
 						      </form>
 						      <form id="ott-form" class="login-form" method="post" action="/ott/generate">
 						        <h2>Request a One-Time Token</h2>
-						     \s
+
 						        <p>
 						          <label for="ott-username" class="screenreader">Username</label>
 						          <input type="text" id="ott-username" name="username" placeholder="Username" required>

config/src/test/java/org/springframework/security/config/http/FormLoginBeanDefinitionParserTests.java

@@ -68,7 +68,7 @@ public class FormLoginBeanDefinitionParserTests {
 				    <div class="content">
 				      <form class="login-form" method="post" action="/login">
 				        <h2>Please sign in</h2>
-				       \s
+
 				        <p>
 				          <label for="username" class="screenreader">Username</label>
 				          <input type="text" id="username" name="username" placeholder="Username" required autofocus>
@@ -115,7 +115,7 @@ public class FormLoginBeanDefinitionParserTests {
 				    <div class="content">
 				      <form class="login-form" method="post" action="/signin">
 				        <h2>Please sign in</h2>
-				       \s
+
 				        <p>
 				          <label for="username" class="screenreader">Username</label>
 				          <input type="text" id="username" name="custom_user" placeholder="Username" required autofocus>

web/src/test/java/org/springframework/security/web/authentication/DefaultLoginPageGeneratingFilterTests.java

@@ -199,12 +199,12 @@ public class DefaultLoginPageGeneratingFilterTests {
 		assertThat(response.getContentAsString()).contains("""
 				      <form id="ott-form" class="login-form" method="post" action="/ott/authenticate">
 				        <h2>Request a One-Time Token</h2>
-				     \s
+
 				        <p>
 				          <label for="ott-username" class="screenreader">Username</label>
 				          <input type="text" id="ott-username" name="username" placeholder="Username" required>
 				        </p>
-				     \s
+
 				        <button class="primary" type="submit" form="ott-form">Send Token</button>
 				      </form>
 				""");