Update for latest Gleam (#138)

* Update for latest Gleam

- Gleam releases now use LLVM triplets for platforms so the download
  URLs have been updated accordingly.
- Gleam's rebar3 support has been removed.

This change means that future versions of this action cannot download
older versions of Gleam. I can make it backwards compatible, but I will
need help from someone who can convert the shell script into PowerShell
for Windows.

* Support older Gleam versions

* Remove rebar from Gleam

test-projects/gleam_gleam/.github/workflows/test.yml

@@ -15,7 +15,7 @@ jobs:
       - uses: erlef/setup-beam@v1.9.0
         with:
           otp-version: "23.2"
-          gleam-version: "0.19.0-rc3"
+          gleam-version: "0.23.0-rc1"
       - run: gleam format --check src test
       - run: gleam deps download
       - run: gleam test

test-projects/gleam_gleam/manifest.toml

@@ -2,8 +2,8 @@
 # You typically do not need to edit this file
 
 packages = [
-  { name = "gleam_stdlib", version = "0.19.2", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "FFA79EA12369F122B68885E694E097D6810402A2F86BFF48AAE9E40ACE654F4C" },
-  { name = "gleeunit", version = "0.6.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "77701A5E5A565727E1EEAC9196FB878D544049B6331CD0305B5A69699135EA1C" },
+  { name = "gleam_stdlib", version = "0.22.3", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "F2C2D389B06426E1289D5419F89BDE8E0F7F35A40B2BBB3C88188481F0D44A9F" },
+  { name = "gleeunit", version = "0.6.2", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "A006864621DB80C4FBB0746580703502FD81A4D38D23FCB20A8120984D353DF0" },
 ]
 
 [requirements]