Add Fedora 39 as supported platform

The actual release code came in an earlier commit. Opening this
commit up now that the release code has been tested.

.release-notes/fedora-39.md

@@ -0,0 +1,3 @@
+## Fedora 39 added as a supported platform
+
+We've added Fedora 39 as a supported platform. We'll be building ponyc releases for it until it stops receiving security updates at the end of 2024. At that point, we'll stop building releases for it.

INSTALL.md

@@ -20,6 +20,7 @@ At the moment, we support all supported LTS Ubuntu versions and any distribution
 
 Currently, we have packages for the following Glibc based distributions:
 
+- Fedora 39
 - Linux Mint 19, 20, 21
 - Pop!_OS 20.04, 22.04
 - Ubuntu 20.04, 22.04
@@ -41,6 +42,7 @@ where `PLATFORM` is from the table below
 Distribution | PLATFORM String
 --- | ---
 Alpine | x86_64-linux-musl
+Fedora 39 | x86_64-linux-fedora39
 Linux Mint 20.x | x86_64-linux-ubuntu20.04
 Linux Mint 21.x | x86_64-linux-ubuntu22.04
 Pop!_OS 20.04 | x86_64-linux-ubuntu20.04

RELEASE_PROCESS.md

@@ -44,6 +44,7 @@ Package names will be:
 
 * ponyc-x86-64-apple-darwin.tar.gz
 * ponyc-x86-64-pc-windows-msvc.zip
+* ponyc-x86-64-unknown-linux-fedora39.tar.gz
 * ponyc-x86-64-unknown-linux-musl.tar.gz
 * ponyc-x86-64-unknown-linux-ubuntu20.04.tar.gz
 * ponyc-x86-64-unknown-linux-ubuntu22.04.tar.gz