Change Version() function to const Version string in otelhttp (#8134)

Author: dogedede

CHANGELOG.md

@@ -1622,3 +1622,7 @@ First official tagged release of `contrib` repository.
 [Go 1.18]: https://go.dev/doc/go1.18
 
 [GO-2024-2687]: https://pkg.go.dev/vuln/GO-2024-2687
+
+### Changed
+
+- Change `Version()` function in `otelhttp` package to a `const Version` string. (#8134)

instrumentation/net/http/otelhttp/version_test.go

@@ -19,6 +19,6 @@ var versionRegex = regexp.MustCompile(`^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)
 	`(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$`)
 
 func TestVersionSemver(t *testing.T) {
-	v := otelhttp.Version()
+	v := otelhttp.Version
 	assert.NotNil(t, versionRegex.FindStringSubmatch(v), "version is not semver: %s", v)
 }