build: remove redundant @types/source-map dependency (#31468)

In version 0.6.1 that we are using, `source-map` ships with
[its own typings][1], so there is no need to use `@types/source-map`.
The types were even removed from `DefinitelyTyped` in
DefinitelyTyped/DefinitelyTyped@1792bfaa2.

[1]: https://github.com/mozilla/source-map/blob/0.6.1/package.json#L72

PR Close #31468

packages/compiler-cli/ngcc/BUILD.bazel

@@ -26,7 +26,6 @@ ts_library(
         "//packages/compiler-cli/src/ngtsc/util",
         "@npm//@types/convert-source-map",
         "@npm//@types/node",
-        "@npm//@types/source-map",
         "@npm//@types/yargs",
         "@npm//canonical-path",
         "@npm//dependency-graph",