Eclipse runs under a particular JVM which is specified in that .ini file. You probably don't need to change that.
When you create a
Java project in Eclipse, you can specify what JVM that project uses. You can download any JVM you like from the web and have that project use it. You can do that for every project, although there's a default JVM if you don't choose one. You can specify what that default
you should be, too. But none of this affects the JVM under which Eclipse runs.
I don't know what the default JVM for Eclipse Photon is, but since that Eclipse version is 6 or 7 years old now I wouldn't be surprised if it's Java 8. Although as I said earlier, it doesn't matter. If you want to have your project use Java 17, then download Java 17 and put it somewhere on your disk. Then find "Installed JREs" in the Java configuration and add the Java 17 JRE to its list.
Although it might be better to get a newer version of Eclipse, don't you think?