Fix calculating -otp- major for Elixir (#351)

* Set expectations

* Ease testing without having to install via `require`

* Code a solution for the tests

* Avoid errors on unit tests

rebar3 is saying something about SSL, most likely because
our tests are installing a bunch of OTPs which makes
for unpredictable behavior

* Avoid errors on integration tests

.github/workflows/action.yml

@@ -76,6 +76,7 @@ jobs:
         uses: ./
         with:
           install-rebar: false
+          install-hex: false
           version-file: test/.tool-versions
           version-type: strict
 

.github/workflows/ubuntu.yml

@@ -25,6 +25,15 @@ jobs:
       fail-fast: false
       matrix:
         combo:
+          - otp-version: '<26'
+            elixir-version: '<1.17'
+            os: 'ubuntu-22.04'
+          - otp-version: 'master'
+            elixir-version: '> 0'
+            os: 'ubuntu-24.04'
+          - otp-version: 'master'
+            elixir-version: 'main'
+            os: 'ubuntu-24.04'
           - otp-version: '27'
             elixir-version: 'v1.17.0'
             rebar3-version: '3.23'

.github/workflows/windows.yml

@@ -25,6 +25,12 @@ jobs:
       fail-fast: false
       matrix:
         combo:
+          - otp-version: '<26'
+            elixir-version: '<1.17'
+            os: 'ubuntu-22.04'
+          - otp-version: 'master'
+            elixir-version: '> 0'
+            os: 'ubuntu-24.04'
           - otp-version: '27'
             elixir-version: 'v1.17.0'
             rebar3-version: '3.23'