Don't run tests on Elixir main on CI

Since 20/01/2023[1], the CI fails on Elixir main during the compilation
of ssl_verify_fun:

    ==> ssl_verify_fun
    Compiling 7 files (.erl)
    src/ssl_verify_fingerprint.erl:15:14: can't find include lib "public_key/include/public_key.hrl"
    %   15| -include_lib("public_key/include/public_key.hrl").
    %     |              ^

    src/ssl_verify_fun_cert_helpers.erl:13:14: can't find include lib "public_key/include/public_key.hrl"
    %   13| -include_lib("public_key/include/public_key.hrl").
    %     |              ^

    src/ssl_verify_fingerprint.erl:27:26: record 'OTPCertificate' undefined
    %   27| -spec verify_fun(Cert :: #'OTPCertificate'{},
    %     |

    ... (more output in the logs[2])

This commit removes Elixir main from the CI matrix to fix the build, but
needs to be reverted at a later date.

[1]: https://appsignal.semaphoreci.com/workflows/74fc0d82-c6ec-4f74-86f2-df89bb7dbac3?pipeline_id=5243b837-baee-4bed-828d-68c1e7464a9b
[2]: https://appsignal.semaphoreci.com/jobs/c9143975-f0a3-426c-b68e-0f5b3b3b5a3b/plain_logs.txt

.semaphore/semaphore.yml

@@ -23,45 +23,40 @@ blocks:
             - script/validate_ci_matrix
         - name: mix compile --warnings-as-errors
           commands:
-            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.14.3 . bin/setup
+            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.13.4 . bin/setup
             - mix compile --warnings-as-errors
         - name: mix format --check-formatted
           commands:
-            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.14.3 . bin/setup
+            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.13.4 . bin/setup
             - mix format --check-formatted
         - name: mix credo --strict
           commands:
-            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.14.3 . bin/setup
+            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.13.4 . bin/setup
             - mix credo --strict
         - name: mix dialyzer
           commands:
-            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.14.3 . bin/setup
+            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.13.4 . bin/setup
             - cache restore dialyzer-plt
             - MIX_ENV=dev mix dialyzer --plt
             - cache store dialyzer-plt priv/plts/
             - MIX_ENV=dev mix dialyzer --format dialyzer
-        - name: Elixir 1.14.3 OTP 25.2 - Diagnose tests
+        - name: Elixir 1.13.4 OTP 25.2 - Diagnose tests
           env_vars:
             - name: LANGUAGE
               value: elixir
             - name: MIX_ENV
               value: dev
           commands:
-            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.14.3 . bin/setup
+            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.13.4 . bin/setup
             - git submodule init
             - git submodule update
             - test/integration/diagnose/bin/test
-        - name: Elixir 1.14.3, OTP 25.2, without the NIF loaded
+        - name: Elixir 1.13.4, OTP 25.2, without the NIF loaded
           env_vars:
             - name: MIX_ENV
               value: test_no_nif
           commands:
-            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.14.3 . bin/setup
-            - mix compile
-            - mix test --no-compile
-        - name: Elixir main, OTP 25.2
-          commands:
-            - ERLANG_VERSION=25.2 ELIXIR_VERSION=main . bin/setup
+            - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.13.4 . bin/setup
             - mix compile
             - mix test --no-compile
         - name: Elixir 1.14.3, OTP 25.2
@@ -74,11 +69,6 @@ blocks:
             - ERLANG_VERSION=25.2 ELIXIR_VERSION=1.13.4 . bin/setup
             - mix compile
             - mix test --no-compile
-        - name: Elixir main, OTP 24.3
-          commands:
-            - ERLANG_VERSION=24.3 ELIXIR_VERSION=main . bin/setup
-            - mix compile
-            - mix test --no-compile
         - name: Elixir 1.14.3, OTP 24.3
           commands:
             - ERLANG_VERSION=24.3 ELIXIR_VERSION=1.14.3 . bin/setup

.semaphore/versions.rb

@@ -1,6 +1,6 @@
 VERSIONS = {
-  "25.2" => ["main", "1.14.3", "1.13.4"],
-  "24.3" => ["main", "1.14.3", "1.13.3", "1.12.3", "1.11.4"],
+  "25.2" => ["1.14.3", "1.13.4"],
+  "24.3" => ["1.14.3", "1.13.3", "1.12.3", "1.11.4"],
   "23.3" => ["1.14.3", "1.13.3", "1.12.3", "1.11.4", "1.10.4"],
   "22.3" => ["1.13.3", "1.12.3", "1.11.4", "1.10.4", "1.9.4"],
   "21.3" => ["1.11.4", "1.10.4", "1.9.4"],