distrodef: fix incorrect detection of centos-10 vs 10.0

This commit fixes the issue that when the `os-release` has a
`10.0` in it, a distrodef ending with `-10` will not be identified
as the closest match.

We saw this issue with the `rhel-10.0` beta that has a
`VERSION_ID=10.0` field and a `rhel-10.yaml` distro-def. Here the
code was skipping over rhel-9.yaml and felt back to rhel-9 when
it really should have used `rhel-10.yaml`.

Thanks to Achilleas for tracking this down.

bib/internal/distrodef/distrodef.go

@@ -51,7 +51,7 @@ func findDistroDef(defDirs []string, distro, wantedVerStr string) (string, error
 			if err != nil {
 				return "", fmt.Errorf("cannot parse distro version from %q: %w", m, err)
 			}
-			if wantedVer.Compare(haveVer) > 0 && haveVer.Compare(bestFuzzyVer) > 0 {
+			if wantedVer.Compare(haveVer) >= 0 && haveVer.Compare(bestFuzzyVer) > 0 {
 				bestFuzzyVer = haveVer
 				bestFuzzyMatch = m
 			}

bib/internal/distrodef/distrodef_test.go

@@ -108,6 +108,16 @@ func TestFindDistroDefMultiFuzzyMinorReleases(t *testing.T) {
 	assert.True(t, strings.HasSuffix(def, "b/b/centos-9.10.yaml"), def)
 }
 
+func TestFindDistroDefMultiFuzzyMinorReleasesIsZero(t *testing.T) {
+	defDirs := makeFakeDistrodefRoot(t, []string{
+		"a/centos-9.yaml",
+		"a/centos-10.yaml",
+	})
+	def, err := findDistroDef(defDirs, "centos", "10.0")
+	assert.NoError(t, err)
+	assert.True(t, strings.HasSuffix(def, "a/centos-10.yaml"), def)
+}
+
 func TestFindDistroDefMultiFuzzyError(t *testing.T) {
 	defDirs := makeFakeDistrodefRoot(t, []string{
 		"a/fedora-40.yaml",