tests: add llvm-toolset-14.0 requirements to tests and plans

tests/basic/main.fmf

@@ -17,3 +17,7 @@ adjust:
       - llvm-toolset-13.0-clang
       - llvm-toolset-13.0-lld
     when: "collection == llvm-toolset-13.0"
+  - require+:
+      - llvm-toolset-14.0-clang
+      - llvm-toolset-14.0-lld
+    when: "collection == llvm-toolset-14.0"

tests/build-gating-alternatives.fmf

@@ -27,6 +27,10 @@ adjust:
     environment+:
       WITH_SCL: "scl enable llvm-toolset-13.0"
     when: "collection == llvm-toolset-13.0"
+  - because: "When testing SCL-ized LLVM, the collection must be enabled first"
+    environment+:
+      WITH_SCL: "scl enable llvm-toolset-14.0"
+    when: "collection == llvm-toolset-14.0"
 
 discover:
     - name: lld-tests

tests/build-gating.fmf

@@ -27,6 +27,10 @@ adjust:
     environment+:
       WITH_SCL: "scl enable llvm-toolset-13.0"
     when: "collection == llvm-toolset-13.0"
+  - because: "When testing SCL-ized LLVM, the collection must be enabled first"
+    environment+:
+      WITH_SCL: "scl enable llvm-toolset-14.0"
+    when: "collection == llvm-toolset-14.0"
 
 discover:
     - name: lld-tests

tests/gcc-compat-basic/main.fmf

@@ -16,3 +16,6 @@ adjust:
   - require+:
       - llvm-toolset-13.0-lld
     when: "collection == llvm-toolset-13.0"
+  - require+:
+      - llvm-toolset-14.0-lld
+    when: "collection == llvm-toolset-14.0"

tests/ld-alternative/main.fmf

@@ -19,3 +19,6 @@ adjust:
   - require+:
       - llvm-toolset-13.0-lld
     when: "collection == llvm-toolset-13.0"
+  - require+:
+      - llvm-toolset-14.0-lld
+    when: "collection == llvm-toolset-14.0"