Make the default github.com path consistent with other paths

On util.ts:223, there is the following comment:

```
// Normalise path to having a trailing slash for consistency
```

However, I notice that the path defined by `GITHUB_DOTCOM_URL`
does not have a trailing slash. This PR fixes it.

lib/util.js

@@ -17,7 +17,7 @@ const apiCompatibility = __importStar(require("./api-compatibility.json"));
 /**
  * The URL for github.com.
  */
-exports.GITHUB_DOTCOM_URL = "https://github.com";
+exports.GITHUB_DOTCOM_URL = "https://github.com/";
 /**
  * Get the extra options for the codeql commands.
  */

lib/util.test.js

@@ -103,10 +103,10 @@ ava_1.default("getExtraOptionsEnvParam() fails on invalid JSON", (t) => {
     process.env.CODEQL_ACTION_EXTRA_OPTIONS = origExtraOptions;
 });
 ava_1.default("parseGithubUrl", (t) => {
-    t.deepEqual(util.parseGithubUrl("github.com"), "https://github.com");
+    t.deepEqual(util.parseGithubUrl("github.com"), "https://github.com/");
-    t.deepEqual(util.parseGithubUrl("https://github.com"), "https://github.com");
+    t.deepEqual(util.parseGithubUrl("https://github.com"), "https://github.com/");
-    t.deepEqual(util.parseGithubUrl("https://api.github.com"), "https://github.com");
+    t.deepEqual(util.parseGithubUrl("https://api.github.com/"), "https://github.com/");
-    t.deepEqual(util.parseGithubUrl("https://github.com/foo/bar"), "https://github.com");
+    t.deepEqual(util.parseGithubUrl("https://github.com/foo/bar"), "https://github.com/");
     t.deepEqual(util.parseGithubUrl("github.example.com"), "https://github.example.com/");
     t.deepEqual(util.parseGithubUrl("https://github.example.com"), "https://github.example.com/");
     t.deepEqual(util.parseGithubUrl("https://api.github.example.com"), "https://github.example.com/");

src/util.test.ts

@@ -126,15 +126,15 @@ test("getExtraOptionsEnvParam() fails on invalid JSON", (t) => {
 });
 
 test("parseGithubUrl", (t) => {
-  t.deepEqual(util.parseGithubUrl("github.com"), "https://github.com");
+  t.deepEqual(util.parseGithubUrl("github.com"), "https://github.com/");
-  t.deepEqual(util.parseGithubUrl("https://github.com"), "https://github.com");
+  t.deepEqual(util.parseGithubUrl("https://github.com"), "https://github.com/");
   t.deepEqual(
-    util.parseGithubUrl("https://api.github.com"),
+    util.parseGithubUrl("https://api.github.com/"),
-    "https://github.com"
+    "https://github.com/"
   );
   t.deepEqual(
     util.parseGithubUrl("https://github.com/foo/bar"),
-    "https://github.com"
+    "https://github.com/"
   );
 
   t.deepEqual(

src/util.ts

@@ -19,7 +19,7 @@ export type Mode = "actions" | "runner";
 /**
  * The URL for github.com.
  */
-export const GITHUB_DOTCOM_URL = "https://github.com";
+export const GITHUB_DOTCOM_URL = "https://github.com/";
 
 /**
  * Get the extra options for the codeql commands.