CI/Runtime: For OTP < 24 use rebar binaries from ejabberd 21.12

.github/workflows/ci.yml

@@ -52,7 +52,7 @@ jobs:
         otp-version: ${{ matrix.otp }}
 
     - name: Get a compatible Rebar3
-      if: matrix.otp <= '21.3'
+      if: matrix.otp < 24
       run: |
         rm rebar3
         wget https://github.com/processone/ejabberd/raw/21.12/rebar3

.github/workflows/runtime.yml

@@ -42,7 +42,7 @@ jobs:
     - uses: actions/checkout@v4
 
     - name: Get compatible Rebar binaries
-      if: matrix.otp < 23
+      if: matrix.otp < 24
       run: |
         rm rebar
         rm rebar3
@@ -170,6 +170,16 @@ jobs:
         otp-version: ${{matrix.otp}}
         elixir-version: ${{matrix.elixir}}
 
+    - name: Get compatible Rebar binaries
+      if: matrix.otp < 24
+      run: |
+        rm rebar
+        rm rebar3
+        wget https://github.com/processone/ejabberd/raw/21.12/rebar
+        wget https://github.com/processone/ejabberd/raw/21.12/rebar3
+        chmod +x rebar
+        chmod +x rebar3
+
     - name: Prepare libraries
       run: |
         sudo apt-get -qq update