Why do I get Caused by: ClassNotFoundException: PostgresSQLDialect even if I have postgress configure din my pom?

My Pom is as shown below. I still get error

Caused by: java.lang.ClassNotFoundException: Could not load requested class : org.hibernate.dialect.PostgresSQLDialect

while running my app.

<modelVersion>4.0.0</modelVersion>
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.4.1</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.pluralsight</groupId>
<artifactId>conference-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>conference-demo</name>
<description>Demo project for Spring Boot</description>

<properties>
    <java.version>15</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>

    <dependency>
        <groupId>org.postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <scope>runtime</scope>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>