slurmrestd - Remove ESLURM_REST_UNKNOWN_URL

Nothing returns ESLURM_REST_UNKNOWN_URL anymore: _req_root() serves the
discovery guidance from a static string, and operations_router() reports
unknown URLs with ESLURM_URL_INVALID_PATH. Drop the error code, its
errtab message and its HTTP status mapping.

Pin ESLURM_REST_UNKNOWN_URL_METHOD to 9007 so the remaining REST error
codes keep the numeric values they shipped with in 25.11 and 26.05;
9006 is retired.

Ticket: 24549

slurm/slurm_errno.h

diff --git a/slurm/slurm_errno.h b/slurm/slurm_errno.h
index f462e69..9f9ca25 100644
--- a/slurm/slurm_errno.h
+++ b/slurm/slurm_errno.h
@@ -417,8 +417,8 @@
 	ESLURM_REST_EMPTY_RESULT,
 	ESLURM_REST_MISSING_UID,
 	ESLURM_REST_MISSING_GID,
-	ESLURM_REST_UNKNOWN_URL,
-	ESLURM_REST_UNKNOWN_URL_METHOD,
+	/* 9006 retired (was ESLURM_REST_UNKNOWN_URL) */
+	ESLURM_REST_UNKNOWN_URL_METHOD = 9007,
 	ESLURM_REST_AUTH_FAIL,
 	ESLURM_REST_BAD_REQUEST,
 

src/common/http.c

diff --git a/src/common/http.c b/src/common/http.c
index 2fde703..c296a52 100644
--- a/src/common/http.c
+++ b/src/common/http.c
@@ -130,7 +130,6 @@
 	T(ESLURM_REST_INVALID_JOBS_DESC, HTTP_STATUS_CODE_ERROR_BAD_REQUEST),
 	T(ESLURM_DATA_UNKNOWN_MIME_TYPE, HTTP_STATUS_CODE_ERROR_UNSUPPORTED_MEDIA_TYPE),
 	T(ESLURM_INVALID_JOB_ID, HTTP_STATUS_CODE_ERROR_NOT_FOUND),
-	T(ESLURM_REST_UNKNOWN_URL, HTTP_STATUS_CODE_ERROR_NOT_FOUND),
 	T(ESLURM_URL_INVALID_PATH, HTTP_STATUS_CODE_ERROR_NOT_FOUND),
 	T(SLURM_PROTOCOL_SOCKET_ZERO_BYTES_SENT, HTTP_STATUS_CODE_SRVERR_BAD_GATEWAY),
 	T(SLURM_COMMUNICATIONS_CONNECTION_ERROR, HTTP_STATUS_CODE_SRVERR_BAD_GATEWAY),

src/common/slurm_errno.c

diff --git a/src/common/slurm_errno.c b/src/common/slurm_errno.c
index 0f8a01d..888eb10 100644
--- a/src/common/slurm_errno.c
+++ b/src/common/slurm_errno.c
@@ -1389,10 +1389,6 @@
 		"Missing UNIX group in the system",
 	},
 	{
-		ERRTAB_ENTRY(ESLURM_REST_UNKNOWN_URL),
-		"Unable to find requested URL endpoint. Please query the '/openapi/v3' endpoint or visit 'https://slurm.schedmd.com/rest_api.html' for the OpenAPI specification which includes a list of all possible slurmrestd endpoints.",
-	},
-	{
 		ERRTAB_ENTRY(ESLURM_REST_UNKNOWN_URL_METHOD),
 		"Requested HTTP query method is not supported at URL endpoint. Please query the '/openapi/v3' endpoint or visit 'https://slurm.schedmd.com/rest_api.html' for the OpenAPI specification which includes a list of all possible slurmrestd endpoints.",
 	},

src/slurmrestd/operations.c

diff --git a/src/slurmrestd/operations.c b/src/slurmrestd/operations.c
index 96cb0f3..05cc408 100644
--- a/src/slurmrestd/operations.c
+++ b/src/slurmrestd/operations.c
@@ -276,7 +276,7 @@
 
 	if (*path_tag == -1)
 		return _operations_router_reject(args, NULL,
-						 ESLURM_REST_UNKNOWN_URL, NULL);
+						 ESLURM_URL_INVALID_PATH, NULL);
 	else if (*path_tag == -2)
 		return _operations_router_reject(args, NULL,
 						 ESLURM_REST_UNKNOWN_URL_METHOD,