Maintentance update to testplans.

* Remove DevTools metadata from plans as collections are no longer
  maintained
* Update tests/README.md
* Sync lld-alternatives testplan

tests/README.md

@@ -1,6 +1,9 @@
 # Gating testplans for LLVM
 
-The tests for LLVM are in a separate repo: https://src.fedoraproject.org/tests/llvm
+The tests for LLVM are in a dedicated, separate repo: https://gitlab.com/redhat/centos-stream/tests/llvm.git
+
 This directory should contain only fmf plans (such as build-gating.fmf) which import
 the tests from the tests repo. This can be done using the "url" parameter of the
-plan's "discover" step. Reference: https://tmt.readthedocs.io/en/stable/spec/plans.html#fmf
+plan's "discover" step.
+
+Reference: https://tmt.readthedocs.io/en/stable/spec/plans.html#fmf

tests/build-gating.fmf

@@ -19,15 +19,6 @@ adjust:
       and trigger != build
     enabled: false
 
-  - because: "When testing SCL-ized LLVM, the collection must be enabled first"
-    environment+:
-      WITH_SCL: "scl enable llvm-toolset-13.0 rust-toolset-1.58"
-    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 rust-toolset-1.62"
-    when: "collection == llvm-toolset-14.0"
-
   # Unfortunatelly, TMT does not support more declarative approach, we need to run commands on our own.
   - because: "On CentOS, CRB must be enabled to provide rarer packages"
     prepare+:
@@ -52,6 +43,7 @@ discover:
     how: fmf
     url: https://gitlab.com/redhat/centos-stream/tests/llvm.git
     ref: main
+    filter: "tag:-spoils-installation & tag:-not-in-default"
 execute:
     how: tmt
 provision:

tests/lld-alternatives.fmf

@@ -0,0 +1,20 @@
+summary: LLD tests for build/PR gating, testing alternatives and spoiling the installation
+adjust:
+  - because: "Plan to be ran when either executed locally, or executed by CI system to gate a build or PR."
+    when: >-
+      trigger is defined
+      and trigger != commit
+      and trigger != build
+    enabled: false
+
+discover:
+    - name: lld-tests
+      how: fmf
+      url: https://gitlab.com/redhat/centos-stream/tests/llvm.git
+      ref: main
+      test: ld-alternative
+execute:
+    how: tmt
+provision:
+  hardware:
+    memory: ">= 4 GiB"