fix: improve fluent-bit binary detection regex pattern (#3701)

* fix: improve fluent-bit binary detection regex pattern

This fixes issue #3133 by updating the regex pattern for fluent-bit binary detection
to better handle ANSI escape sequences and multiple null bytes between the version
string and "Fluent Bit" text. The change also makes the %s format specifier optional,
supporting all variations in fluent-bit binary signatures.

Signed-off-by: Alan Pope <alan.pope@anchore.com>

* test: add fluent-bit 1.7.0-dev-3 test fixture for issue #3133

Signed-off-by: Alan Pope <alan.pope@anchore.com>

---------

Signed-off-by: Alan Pope <alan.pope@anchore.com>

syft/pkg/cataloger/binary/classifier_cataloger_test.go

@@ -1221,6 +1221,17 @@ func Test_Cataloger_PositiveCases(t *testing.T) {
 				Metadata:  metadata("fluent-bit-binary"),
 			},
 		},
+		{
+			logicalFixture: "fluent-bit/1.7.0-dev-3/linux-amd64",
+			expected: pkg.Package{
+				Name:      "fluent-bit",
+				Version:   "1.7.0",
+				Type:      "binary",
+				PURL:      "pkg:github/fluent/fluent-bit@1.7.0",
+				Locations: locations("fluent-bit"),
+				Metadata:  metadata("fluent-bit-binary"),
+			},
+		},
 		{
 			logicalFixture: "wp/2.9.0/linux-amd64",
 			expected: pkg.Package{

syft/pkg/cataloger/binary/classifiers.go

@@ -572,7 +572,8 @@ func DefaultClassifiers() []Classifier {
 				// [NUL]3.0.2[NUL]%sFluent Bit
 				// [NUL]2.2.3[NUL]Fluent Bit
 				// [NUL]2.2.1[NUL][NUL][NUL]Fluent Bit
-				`\x00(?P<version>[0-9]+\.[0-9]+\.[0-9]+)\x00[^\d]*Fluent`,
+				// [NUL]1.7.0[NUL]\x1b[1m[NUL]%sFluent Bit (versions 1.7.0-dev-3 through 1.7.0-dev-9 and 1.7.0-rc4 through 1.7.0-rc8)
+				`\x00(?P<version>[0-9]+\.[0-9]+\.[0-9]+)\x00(\x1b\[1m\x00|\x00\x00)?(%s)?Fluent`,
 			),
 			Package: "fluent-bit",
 			PURL:    mustPURL("pkg:github/fluent/fluent-bit@version"),

syft/pkg/cataloger/binary/test-fixtures/config.yaml

@@ -688,6 +688,13 @@ from-images:
     paths:
       - /fluent-bit/bin/fluent-bit
 
+  - version: 1.7.0-dev-3
+    images:
+      - ref: fluent/fluent-bit:1.7.0-dev-3@sha256:d8105ebefa27ca7d8ad2233ab0a4364ff43a9b31c484bde27f0d3d18988b34a0
+        platform: linux/amd64
+    paths:
+      - /fluent-bit/bin/fluent-bit
+
   - name: openssl
     version: 1.1.1w
     images: