btf: re-enable libbpf feature-detection fix (0001)

Run 31221646782 with all six btf workarounds disabled failed every
android12-5.10 build (all 38 sublevels) in the same spot: libbpf's
feature-detection builds an elfdep test binary with clang, which fails
with 'Executable "ld" doesn't exist' in the hermetic PATH, so
libbpf.a never builds and resolve_btfids cannot be built. 0001 removes
the feature-detection steps from tools/lib/bpf/Makefile and is
load-bearing for every sublevel. The other five fixes stay disabled.

.github/actions/btf/action.yml

@@ -17,7 +17,7 @@ runs:
     - name: Apply libbpf feature-detection fix (android12-5.10)
       shell: bash
       working-directory: ${{ github.workspace }}/kernel/common
-      if: false
+      if: ${{ inputs.version == 'android12-5.10' }}
       run: |
         set -euo pipefail
         patch -p1 -N < ${{ github.action_path }}/patches/0001-libbpf-remove-feature-detection-BTF.patch